How I build my C4 Carputer

[joerg]

Hello odroid community, I just want to show how is looking Lawnchair Launcher with a custom menu drawer on Lineage 17.
This menu I created years ago to use with the C2 in my car. Now I have polished the favorites part and integrated it into Lawnchair.
I don't like to much app starters on the home screen, better none of them.
On the home screen there are three dots in left downer corner to open the menu.

Screenshot_20200603-134318_Lawnchair.png (1 MiB) Viewed 13644 times

A list of all apps...

Screenshot_20200603-134216_Lawnchair.png (624.04 KiB) Viewed 13644 times

Favorites...

Screenshot_20200603-135623_Lawnchair.png (827.19 KiB) Viewed 13644 times

Adding apps to favorites...

Screenshot_20200603-140104_Lawnchair.png (614.77 KiB) Viewed 13644 times

BTW. I am waiting the pcb for the car interface board to finalize this project (C4 Carputer). It's as of DHL on the way...
...but I don't know if it ever will be in my hands

Code: Select all

2020-06-02 23:34:36 Uncontrollable Clearance Delay
2020-06-02 08:16:00 Uncontrollable Clearance Delay
2020-05-31 17:42:00 Uncontrollable Clearance Delay
2020-05-31 16:02:24 Processed for clearance at LEIPZIG-DEU
2020-05-31 15:27:06 Arrived at Sort Facility LEIPZIG-DEU
2020-05-30 06:43:58 Departed Facility in HONG KONG-HKG
2020-05-30 06:23:47 Processed at HONG KONG-HKG
2020-05-29 23:23:00 Uncontrollable Clearance Delay
2020-05-29 21:43:33 Processed for clearance at LEIPZIG-DEU
2020-05-29 19:09:08 Arrived at Sort Facility LEIPZIG-DEU
2020-05-29 17:13:38 Processed at HONG KONG-HKG
2020-05-29 11:54:59 Customs status updated
2020-05-29 11:15:14 Processed at DUBAI-ARE
2020-05-29 07:27:58 Departed Facility in HONG KONG-HKG
2020-05-28 23:26:43 Clearance processing complete at HONG KONG-HKG
2020-05-28 22:11:21 Arrived at Sort Facility HONG KONG-HKG
2020-05-28 18:58:00 Customs status updated
2020-05-28 18:06:58 Departed Facility in SHENZHEN-CHN
2020-05-28 18:05:53 Processed at SHENZHEN-CHN
2020-05-28 18:04:52 Arrived at Sort Facility SHENZHEN-CHN
2020-05-28 13:05:27 Customs status updated
2020-05-28 16:50:51 Shipment picked up 

[joerg]

Finally the pcb (10 pcs.) has arrived.

IMG_20200610_160300.jpg (926.71 KiB) Viewed 13568 times

IMG_20200610_160204.jpg (879.8 KiB) Viewed 13568 times

[joerg]

I have designed my pcb for the Toslink/spdif footprint PLT133/T10W, but I find it very difficult to get them. There are only few distributors like Digi-Key with delivery at high costs. Also they don't have the PLT133 in stock, but the nearly identical EAPLTAA6, also from Everlight.
Now I found another device that has the same footprint: Cliff OTJ-8 FCR684208T. It has some less bit rate, as datasheet 12.5Mbps (PLT133: 16Mbps). There are more distributors for the OTJ8. I bought two in Germany at Conrad.

[rooted]

Your boards turned out really nice, I hope you got all the traces and components right so you won't need another revision

[joerg]

Thank you, @rooted. I haven't tested all, but the mayor part.
Here is how it looks, not yet in the car. To assemble into the car, I need to make a housing first.

IMG_20200611_151313.jpg (502.78 KiB) Viewed 13529 times

IMG_20200611_151635.jpg (554.99 KiB) Viewed 13529 times

The switch is for simulating the ignition wire.
When the 12V connector is plugged in then the gpio of the ATiny that controls the power fet is for some milli seconds on and the fuse is opening due to the in rush current. This it makes two or three times and causes the ATiny to reboot. But not always. I think I will change the 3.15A super fast fuse to a slower one to avoid this. This is a minor issue, as the connection of the 12V not so often happens when it is assembled in the car.

[joerg]

Here I post again the shematic of the pcb.

C4 Car Interface.png (89.36 KiB) Viewed 13516 times

[mad_ady]

It fits nicely, great job!

[joerg]

Looks great!

[Tenaja]

Looks like a neat project

[joerg]

I have created another service app that regulates the pwm fan. It reads the temperatures of zone0 and zone1 and sets the duty cycle by calculation (temp - 25) * 15 * 1000. So it will be 75% at 75°C and 37.5% at 50°C. I need to polish it a little, means making this calculation be settable in prefences. I am using a refurbished 5V fan from notebook.

Screenshot_20200612-204842_Lawnchair.png (423.99 KiB) Viewed 13462 times

BTW, it would be great if setting pwm is possible by Android Things. But I assume it's not yet available?

[rooted]

That's awesome, you keep banging out those super useful apps that make using as a carputer so much nicer.

[joerg]

The app for controlling the pwm fan is ready:
V1.1.1
-pwm number (0|1) can be edited in settings (Why this? Pls. read in viewtopic.php?p=312663#p312663)

TemperatureService-V1.1.1.zip

(1.54 MiB) Downloaded 114 times

V1.1.0
-New preference and function 'Low limit temperature to switch off PWM'. The hysteresis is 5°C.
-Changed default frequency to 12kHz

I made it open source : https://github.com/joerg65/TemperatureService
It is limited to work only on C4 and N2. On N2 I haven't tried it yet.
The settings page is written in English, German and Spanish.
The image draws the linear function as the settings are applied. To show how the duty cycle relates to the temperature.

Screenshot_20200614-204548_Temperature_Service.png (35.25 KiB) Viewed 13398 times

Screenshot_20200614-204529_Temperature_Service.png (29.6 KiB) Viewed 13202 times

It's designed for only landscape screen. On other screen than VU7+ it might look not so fine.

[joerg]

The next step is to make a housing for the C4, the interface board and a fan. As I don't own a 3d printer, it will be made by handwork.
I have reserved some of the pcb, but 3 of them I can give away, unsoldered...pls. contact me by pn, if there is demand.

[joerg]

Some more details for the pcb:

B.png (59.15 KiB) Viewed 13343 times

F.png (68.86 KiB) Viewed 13343 times

BOM:

Code: Select all

"Source:","C4 Car Interface.sch"
"Date:","Mo 15 Jun 2020 18:16:09 CEST"
"Tool:","Eeschema 5.1.6-c6e7f7d~86~ubuntu18.04.1"
"Component Count:","39"
"Ref","Value","Footprint"
"BT1","CR1220","user:BatteryHolder_SMTU1220-SMT"
"C1","100","Capacitor_SMD:C_1206_3216Metric_Pad1.42x1.75mm_HandSolder"
"C2","1u","Capacitor_SMD:C_1206_3216Metric_Pad1.42x1.75mm_HandSolder"
"C3","22","Capacitor_SMD:C_1206_3216Metric_Pad1.42x1.75mm_HandSolder"
"C4","22","Capacitor_SMD:C_1206_3216Metric_Pad1.42x1.75mm_HandSolder"
"D1"," 5.0SMDJ15CA","Diode_SMD:D_SMC_Handsoldering"
"D2","3V3","ZenerDiode_SMD:D_MiniMELF"
"D4","1N4148","Diode_SMD:D_MiniMELF"
"D5","BLUE","LED_SMD:LED_1206_3216Metric_Pad1.42x1.75mm_HandSolder"
"F1","3.15","Fuse:Fuse_Littelfuse_372_D8.50mm"
"J1","3p male","Connector_Phoenix_MC:PhoenixContact_MC_1,5_3-G-3.81_1x03_P3.81mm_Horizontal"
"J2","02x20","Connector_PinSocket_2.54mm:PinSocket_2x20_P2.54mm_Vertical"
"J3","01x02","Connector_PinSocket_2.54mm:PinSocket_1x02_P2.54mm_Vertical"
"J4","01x02","TerminalBlock_4Ucon:TerminalBlock_4Ucon_1x02_P3.50mm_Vertical"
"J5","02x03","Connector_PinHeader_2.54mm:PinHeader_2x03_P2.54mm_Horizontal"
"J6","2p male","Connector_Phoenix_MC:PhoenixContact_MC_1,5_2-G-3.81_1x02_P3.81mm_Horizontal"
"J7","01x07","Connector_PinSocket_2.54mm:PinSocket_1x07_P2.54mm_Vertical"
"L1","SRP1265A-470","user:L_Bourns_SRR1265_Handsolder"
"Q1","SI4447","Package_SO:SOIC-8_3.9x4.9mm_P1.27mm"
"Q2","BC847","Package_TO_SOT_SMD:SOT-23"
"Q3","FMMT618","Package_TO_SOT_SMD:SOT-23"
"R1","2k7","Resistor_SMD:R_1206_3216Metric_Pad1.42x1.75mm_HandSolder"
"R2","1k","Resistor_SMD:R_1206_3216Metric_Pad1.42x1.75mm_HandSolder"
"R3","3k3","Resistor_SMD:R_1206_3216Metric_Pad1.42x1.75mm_HandSolder"
"R4","10k","Resistor_SMD:R_1206_3216Metric_Pad1.42x1.75mm_HandSolder"
"R5","1k","Resistor_SMD:R_1206_3216Metric_Pad1.42x1.75mm_HandSolder"
"R6","2k","Resistor_SMD:R_1206_3216Metric_Pad1.42x1.75mm_HandSolder"
"R7","2k","Resistor_SMD:R_1206_3216Metric_Pad1.42x1.75mm_HandSolder"
"R8","3k3","Resistor_SMD:R_1206_3216Metric_Pad1.42x1.75mm_HandSolder"
"R9","3k3","Resistor_SMD:R_1206_3216Metric_Pad1.42x1.75mm_HandSolder"
"R10","330","Resistor_SMD:R_1206_3216Metric_Pad1.42x1.75mm_HandSolder"
"R11","100","Resistor_SMD:R_1206_3216Metric_Pad1.42x1.75mm_HandSolder"
"R12","470","Resistor_SMD:R_1206_3216Metric_Pad1.42x1.75mm_HandSolder"
"SW1","RND 210-00255","user:SW_PUSH_6mm_H8.5mm"
"U1","MCP1703A-3302","Package_TO_SOT_SMD:SOT-23"
"U2","ATtiny85-20SU","Package_SO:SOIJ-8_5.3x5.3mm_P1.27mm"
"U3","DS3231M","Package_SO:SOIC-16W_7.5x10.3mm_P1.27mm"
"U4","PLT133-T10W","user:Everlight_PLT133_T10W"

All capacitors are ceramic.
R8 and R9 are not really needed. I learned in other thread that C4 has already 1k pull up resistors.
Without yellow Led it won't work! The Led acts as a Zener Diode.
For the power supply of the C4 must be soldered a header at J3. https://wiki.odroid.com/odroid-c4/appli ... ower_input
Alternatively there is another connector J6 to connect the power, if there is no trust in the header connection.

[joerg]

Nearly ready with the housing. But as I said, it's hand made from soft pvc plates, that can be cut by knife and glued with a vulcanizing glue.
Then I went with my car for a first test and it worked basically everything: Spdif music listening, Gps navigating, Hilink modem Internet. The pwm fan makes noises with 1000Hz, also with 500Hz. I reduced the frequency to 100Hz, now it's less noisy.
On the picture is seen that there is a gap between the 40p header and the connector. It is meant for the air flow. I have to make and put some supports that makes the air go through the air gap to pass the cooling element.

It's not a beauty!

IMG_20200617_103454.jpg (365.94 KiB) Viewed 13286 times

IMG_20200617_103821.jpg (398.26 KiB) Viewed 13286 times

[odroid]

It is beautiful
Making an air gap is a brilliant idea indeed.

BTW, it is worth to try 25~30Khz of PWM frequency to lower the fan motor noise probably.

[joerg]

It is beautiful
Making an air gap is a brilliant idea indeed.

Thank you for the flowers!

BTW, it is worth to try 25~30Khz of PWM frequency to lower the fan motor noise probably.

I will check this due to the maximum power dissipation of 625mW of the FMMT618.
I need to measure the current and the du/dt of the switch to have an idea of the thermal loss.

[joerg]

Thank you @odroid, I tried different pwm frequencies. The power stage is not well designed for frequency > 20kHz. The switch off takes about 25us, the switch on 3.4us. I tried another freewheeling diode, a faster one as 1N4148, but the behavior is the same.
But I have also low noise at frequencies of 12 - 16kHz. The power loss with this kind of fan I use is about <200mW. The fan takes 250mA. The main power loss is at switch on and off. During constant switch on phase it's about 3mW and not need to be taken in account.
Because of the switch off ramp the signal is looking as triangle at higher frequencies than 20kHz.
I checked also with finger and with thermometer, no significant warming a the FMMT618.
I will stay with 12kHz. As this is a good compromise of switch characteristic and noise.

[mad_ady]

Since it will be in a car - will noise matter?

[joerg]

@mad_ady, yes the noise at 1kHz was ugly penetrate. And some times I am sitting in the car waiting, without motor on, than it comes to foreground.

[joerg]

Here is the hex file for the ATtiny85 on the pcb:

TinyC4.hex.zip

(1021 Bytes) Downloaded 109 times

To flash it I use this avrdude command from Eclipse UI:
/usr/bin/avrdude -pt85 -cavrisp2 -P/dev/ttyACM0 -u -Uflash:w:TinyC4.hex:a -Ulfuse:w:0x62:m -Uhfuse:w:0xdf:m -Uefuse:w:0xff:m

A small description of the code:
* With Ignition On the ATtiny wakes up. The Output pin Enable will be switched On and the Power-FET connects power to the C4.
* The Ignition is internally rooted to Shutdown pin PB4 that is connected to GPIO 24 of C4, and there the pin should be set up as Shutdown.
* When Ignition switches to Off then C4 should initiate a shutdown and finally after delay time the 5V will be off and the ATtiny will go to sleep.
* If the Reboot button is pressed short time, the ATtiny does nothing, the button is also connected to GPIO 27 of C4 and should cause a reboot.
* Pressing the button more than 2s will cause a power cycle to the C4.

[joerg]

I have installed and running it since a couple of days. It's running fine.
These days we have > 30°C in Germany and today and yesterday I was at customers and in the afternoon came back to my car that was all day in full sun. Today I made a check, switched off the pwm fan and also cars' climate control, only opened the windows. The temperature of the C4 went to 65°C, some of my services running, music player and navigation app. Then I switched on the pwm fan, the temperature went down to 38 - 40°C with duty cycle of ~33%.
It shows me that it may work if people don't want to use an extra fan in a car installation. But I will stay with it! For the lifetime of an electronic system it is better when temperature is controlled, not so much deviation.

[mad_ady]

I wonder how hot do built-in stereo/navigation system run? I doubt they have cooling fans, but they may be less powerful...

[Tenaja]

Very large, exposed heat sinks.

[joerg]

I have soldered one board and I have programmed and tested it. If someone wants it, please pm me. There are more 3 empty boards, I can solder them too.

[joerg]

I was asked to publish the source code of the Attiny85 on the board.
Here it is with a corresponding makefile:

TinyC4.zip

(7.53 KiB) Downloaded 102 times

To compile it, it need some packages to be installed on your Linux host:

Bildschirmfoto vom 2020-07-26 16-53-15.png (28.6 KiB) Viewed 12095 times

A simple make will compile it:

Code: Select all

~/Development/eclipse/TinyC4 $ make

-------- begin --------
avr-gcc (GCC) 5.4.0
Copyright (C) 2015 Free Software Foundation, Inc.
Dies ist freie Software; die Kopierbedingungen stehen in den Quellen. Es
gibt KEINE Garantie; auch nicht für MARKTGÄNGIGKEIT oder FÜR SPEZIELLE ZWECKE.


Compiling C: main.c
avr-gcc -c -mmcu=attiny85 -I. -gdwarf-2 -DF_CPU=1000000UL -Os -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums -Wall -Wstrict-prototypes -Wa,-adhlns=./main.lst  -std=gnu99 -Wundef -MMD -MP -MF .dep/main.o.d main.c -o main.o 

Linking: main.elf
avr-gcc -mmcu=attiny85 -I. -gdwarf-2 -DF_CPU=1000000UL -Os -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums -Wall -Wstrict-prototypes -Wa,-adhlns=main.o  -std=gnu99 -Wundef -MMD -MP -MF .dep/main.elf.d main.o --output main.elf -Wl,-Map=main.map,--cref     -lm

Creating load file for Flash: main.hex
avr-objcopy -O ihex -R .eeprom -R .fuse -R .lock main.elf main.hex

Creating load file for EEPROM: main.eep
avr-objcopy -j .eeprom --set-section-flags=.eeprom="alloc,load" \
--change-section-lma .eeprom=0 --no-change-warnings -O ihex main.elf main.eep || exit 0

Creating Extended Listing: main.lss
avr-objdump -h -S -z main.elf > main.lss

Creating Symbol Table: main.sym
avr-nm -n main.elf > main.sym

Size after:
   text	   data	    bss	    dec	    hex	filename
    770	      0	     15	    785	    311	main.elf

The main.hex is the file that need to be flashed.
I use a cheap usb avr programmer for that:

IMG_20200726_170644.jpg (304.94 KiB) Viewed 12095 times

The 6p cable need to be plugged with red mark to pin 1, as it can be seen.
The command to flash:

Code: Select all

avrdude -pt85 -cavrispv2 -P/dev/ttyACM0 -Uflash:w:main.hex:a -Ulfuse:w:0x62:m -Uhfuse:w:0xdf:m -Uefuse:w:0xff:m

Code: Select all

~/Development/eclipse/TinyC4 $ avrdude -pt85 -cavrispv2 -P/dev/ttyACM0 -Uflash:w:main.hex:a -Ulfuse:w:0x62:m -Uhfuse:w:0xdf:m -Uefuse:w:0xff:m
avrdude: stk500v2_ReceiveMessage(): timeout

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.00s

avrdude: Device signature = 0x1e930b (probably t85)
avrdude: NOTE: "flash" memory has been specified, an erase cycle will be performed
         To disable this feature, specify the -D option.
avrdude: erasing chip
avrdude: reading input file "main.hex"
avrdude: input file main.hex auto detected as Intel Hex
avrdude: writing flash (770 bytes):

Writing | ################################################## | 100% 0.21s

avrdude: 770 bytes of flash written
avrdude: verifying flash memory against main.hex:
avrdude: load data flash data from input file main.hex:
avrdude: input file main.hex auto detected as Intel Hex
avrdude: input file main.hex contains 770 bytes
avrdude: reading on-chip flash data:

Reading | ################################################## | 100% 0.16s

avrdude: verifying ...
avrdude: 770 bytes of flash verified
avrdude: reading input file "0x62"
avrdude: writing lfuse (1 bytes):

Writing | ################################################## | 100% 0.01s

avrdude: 1 bytes of lfuse written
avrdude: verifying lfuse memory against 0x62:
avrdude: load data lfuse data from input file 0x62:
avrdude: input file 0x62 contains 1 bytes
avrdude: reading on-chip lfuse data:

Reading | ################################################## | 100% 0.00s

avrdude: verifying ...
avrdude: 1 bytes of lfuse verified
avrdude: reading input file "0xdf"
avrdude: writing hfuse (1 bytes):

Writing | ################################################## | 100% 0.01s

avrdude: 1 bytes of hfuse written
avrdude: verifying hfuse memory against 0xdf:
avrdude: load data hfuse data from input file 0xdf:
avrdude: input file 0xdf contains 1 bytes
avrdude: reading on-chip hfuse data:

Reading | ################################################## | 100% 0.00s

avrdude: verifying ...
avrdude: 1 bytes of hfuse verified
avrdude: reading input file "0xff"
avrdude: writing efuse (1 bytes):

Writing | ################################################## | 100% 0.01s

avrdude: 1 bytes of efuse written
avrdude: verifying efuse memory against 0xff:
avrdude: load data efuse data from input file 0xff:
avrdude: input file 0xff contains 1 bytes
avrdude: reading on-chip efuse data:

Reading | ################################################## | 100% 0.00s

avrdude: verifying ...
avrdude: 1 bytes of efuse verified

avrdude: safemode: Fuses OK (E:FF, H:DF, L:62)

avrdude done.  Thank you.

[odroid]

Thank you for the detail instruction. Luckily, I have an AVR ISPv2 compatible device too.

[joerg]

I soldered one board without rtc and fan components. It fits onto the N2+.

IMG_20200727_204241.jpg (302.1 KiB) Viewed 12039 times

I left also the headers J3 and J7 away. On J7 I soldered only one pin to connect the spdif signal with a jumper wire.

[joerg]

Posted a newer version of app TemperatureService.
BTW. I still have some printed boards. Can be soldered by me.

[cmderkeen]

Hi Joerg,

I'm a new forum user, so I can't PM you. Can you disclose how much your C4 Carputer board costs?

Does it incorporate an RTC?

Is there a way to control volume using a potentiometer?

[joerg]

HI BR,

I don't have an existing radio system in my car. So the C4 will be completely standalone in my implementation.

The reset switch will be useful for me if it can be accessible on the front of the head unit frame that holds the touch screen. Would it work if you left the switch off the board, so that I could wire a remote switch similar to the Hardkernel one to the same holes of your onboard switch?

My question about the amplifier is more to do with my car not having any existing audio system.
I've found a standalone DAC that has the same mounting holes as a PI/C4 https://shop.justboom.co/products/justboom-dac
This way I can stack it on top of the C4 and your card. But this DAC isn't an amplifier, so do I still need a separate amplifier? Or does your card have enough power to drive my car's passive speakers?
There is another standalone amp that the same company makes which can be stacked on top of the DAC: https://shop.justboom.co/products/justboom-amp

@cmderkeen, I tried now (and I found also a bug in the ATtiny prog ).
Sure you can solder an external switch, if I don't solder one on the board. But it can't be mixed with the Hardkernel solution of power button! (It means, the wake up function)
It's because of the design. My board switches off the whole power, when the ignition is off and the C4 is ready with delayed shutdown. Then the C4 is without any power and a power button can't wake it up.
When you solder an external button, it does work as this: A short press would make a reboot of the C4 if the pin is configured in my GpioShutdown app. A long press about 2 seconds will make a power cycle, this is managed by the ATtiny uC. With the power cycle the C4 will reboot, but hard. And I think that is what you are thinking about.

My car only has two 4inch 4ohm stereo speakers at the front anyway, so there's not much power needed to drive them.

I'll wait to hear back from you to find out if the experiment with a remote switch works. Yes, that's what I intend the switch for, so that if the C4 freezes, I can do a hard reboot from the front of the head unit. I'm thinking of drilling a hole in the top right of this frame: https://lilliputdirect.com/lilliput-ope ... -din-frame to mount the switch.

I've reached out to Justboom as well, to see if a rotary volume knob can be added to their amp. They have instructions https://www.justboom.co/tutorials/add-a ... alone-amp/ on how to put an inline potentiometer before the amp. But if I connect their DAC and amp together, then that inline terminal won't work anymore. I'm hoping I can do the reverse instead, and put the potentiometer between the amp's line out and the speakers.

Sure, if you have two 4" speakers, this amplifier could be enough. And as I see right, you can install a potentiometer between the DAC and the amplifier. As they wrote, for volume control should be used logarithmic ones.

[joerg]

Here is a new version of the ATtiny prog with a bugfix.
The bug was that with long button press from time to time the power was not switched on and the C4 didn't start up. A total power cycle was needed then.

TinyC4.hex.zip

(1.03 KiB) Downloaded 82 times

Code: Select all

/*********************************************************************
* C4 Interface
*
* joerg.wolff@gmx.de  06.2020
*
*               ATtiny85 Pin map
*
*                    +-\/-+
*              PB5  1|o   |8  VCC
*        5V_ON PB3  2|    |7  PB2  ENABLE
*     SHUTDOWN PB4  3|    |6  PB1  REBOOT
*              GND  4|    |5  PB0  IGNITION
*                    +----+
*
*
* With Ignition On the ATtiny wakes up. The Output pin Enable will be switched On and the Power-FET connects power to the C4.
* The Ignition is internally rooted to Shutdown pin PB4 that is connected to GPIO 24 of C4, that should be set up as Shutdown.
* When Ignition switches to Off then C4 should initiate a shutdown and finally the 5V will be off and the ATtiny will go to sleep.
* If the Reboot button is pressed short time, the ATtiny does nothing, the button is also connected to GPIO 27 of C4 and should cause a reboot.
* Pressing the button more than 2s will cause a power cycle.
*
*
**********************************************************************/
#include <avr/io.h>
#include <avr/iotn85.h>
#include <avr/interrupt.h>
#include <avr/interrupt.h>
#include <util/delay.h>
#include <avr/sleep.h>
#include <avr/power.h>
#include <util/delay.h>

// Output Enable Pin 7
#define EN  PB2

// Output Ignition to C4 Pin 3 (SHUTDOWN)
#define IGN_OUT PB4

// Input Hold Pin 2 (5V_ON)
#define HOLD PB3

// Input Ein Pin 5 (IGNITION)
#define ON PB0

// INPUT Reboot (C4)
#define RESET PB1

volatile uint16_t cnt_1ms;
volatile uint16_t tm_in0;
volatile uint16_t tm_in1;
volatile uint16_t tm_in2;
volatile uint16_t tm_reset;
volatile uint16_t tm_offdelay;
volatile uint16_t tm_hardresetdelay;

volatile uint8_t pulse;
  
//*********************************************************************
// Timer
ISR (TIMER0_COMPA_vect)
{
	// Timer Interrupt every 1ms
	cnt_1ms++;
	if (cnt_1ms >= 1000){
		cnt_1ms = 0;
		pulse = ~pulse;
	}


	//Counter
	tm_in0++;
	tm_in1++;
	tm_in2++;
	tm_reset++;
	if (tm_reset > 2500) {
		tm_reset = 2500;
	}

	tm_offdelay--;
	if (tm_offdelay == 0xffff) {
		tm_offdelay = 0;
	}

	tm_hardresetdelay--;
	if (tm_hardresetdelay == 0xffff) {
		tm_hardresetdelay = 0;
	}

}

// Pin change interrupt
ISR (PCINT0_vect)
{
	//To avoid massive interrupts
	//disable pin change interrupts
	GIMSK &= ~(1<<PCIE);

	//ensure that the cpu desn't go to sleep immediately
	if ((PINB & ( 1 << ON))) {
		tm_offdelay = 1000;
	}
}

//*********************************************************************
// Setup Ports and Timer
void setup(void) {

	DDRB  	 |= (1 << EN);	    // EN-Pin (Power-FET)
	PORTB &= ~(1<<EN);          // Off

	DDRB  &= ~(1<<ON);          // Pin On (Ignition) Input
	PORTB |= (1<<ON);           // Pull-Up


	DDRB  &= ~(1<<HOLD);        // Pin Hold (5V_ON) Input
	PORTB |= (1<<HOLD);         // Pull-Up

	DDRB  	 |= (1 << IGN_OUT);	// Shutdown Output
	PORTB &= ~(1<<IGN_OUT);		// Off

	DDRB  &= ~(1<<RESET);       // Reboot Input
	PORTB |= (1<<RESET);        // Pull-Up
	
	// Configure Timer 0
	TCCR0A = (1<<WGM01);        // CTC Modus
	TCCR0B |= (1<<CS01);        // Prescaler 8
	                            // ((1000000/8)/1000) = 125
	OCR0A = 125-1;              // 1 ms

	// Compare Interrupt
	TIMSK |= (1<<OCIE0A);

	// pin change interrupt
	PCMSK  = (1<<PCINT0);       // want pin PB0 IGNITION to wake up from sleep
	GIFR  |= (1<<PCIF);         // clear any outstanding interrupts
	GIMSK |= (1<<PCIE);         // enable pin change interrupts

	ADCSRA = 0;
  
	sei();
}

void goToSleep (void)
{

	set_sleep_mode (SLEEP_MODE_PWR_DOWN);
	cli ();
	GIMSK |= (1<<PCIE);         // enable pin change interrupts
	sleep_enable ();
	sei ();
	sleep_cpu ();
	sleep_disable ();
}

//*********************************************************************
// Main
int main(void)
{
	uint8_t hold, en, reset, hard_reset, off_delay;
	uint8_t hold_old;
	uint8_t on_switch;

	tm_in0 = 5000;
	cnt_1ms = 0;
	hold = 0;
	hold_old = 0;
	reset = 0;
	hard_reset = 0;
	on_switch = 0;
	en = 0;
	off_delay = 0;
	pulse = 0;

	setup();

	//forever
	for(;;)	{

		_delay_ms(2);

		en = 0;

		// Ignition

		if ((PINB & ( 1 << ON))) {
			if (tm_in0 >= 20) {
				//Debouncing
				tm_in0 = 20;
				on_switch = ~0;
				PORTB |= (1<<IGN_OUT);
			}
		} else {
			on_switch = 0;
			tm_in0 = 0;
			PORTB &= ~(1<<IGN_OUT);
		}



		// Hold (5V_ON)
		if ((PINB & ( 1 << HOLD))) {
			if (tm_in1 >= 20) {
				tm_in1 = 20;
				hold = ~0;
			}
		} else {
			hold = 0;
			tm_in1 = 0;
		}

		//Only falling edge: off_delay 2000ms
		if ((hold == 0) & (hold_old != 0)) {
			tm_offdelay = 2000;
		}
		hold_old = hold;

		if (tm_offdelay > 0) {
			off_delay = ~0;
		} else {
			off_delay = 0;
		}

		// Reset button
		if ((PINB & ( 1 << RESET))) {
			//Debouncing
			if (tm_in2 >= 20) {
				tm_in2 = 20;
				reset = ~0;
			}
		} else {
			reset = 0;
			tm_in2 = 0;
		}
		if ((reset == 0) & (hold > 0))  {
			if (tm_reset > 2000) {
				//User pressed Reset button > 2s
				hard_reset = ~0;
				tm_hardresetdelay = 500;
			}
		} else {
			tm_reset = 0;
		}
		if (tm_hardresetdelay == 0) hard_reset = 0;

		//Debug
		/*
		if (pulse) {
			PORTB |= (1<<IGN_OUT);
		} else {
			PORTB &= ~(1<<IGN_OUT);
		}*/

		en |= hold;
		en |= on_switch;
		en |= off_delay;
		en &= ~hard_reset;

		//Debug
		//en=(PINB & ( 1 << ON));
		//en = hold;

		// Enable
		if (en > 0) {
			//Switch on Power-FET
			PORTB |= (1<<EN);
		} else {
			//Switch off Power-FET
			PORTB &= ~(1<<EN);
		}

		if ((en == 0) & (on_switch == 0)) {
			goToSleep();
		}

	}//for.end
}

[joerg]

Here is a Live Wallpaper I just made. It's to show a logo like a car company logo on the home screen. The logo will move over the screen and touching a border changes the direction.
I have found that using it on larger screens than a VU7 (1024x600) makes the load bigger and the motion not so smooth. It's because the background needs to repainted, I use canvas for it. The bigger the screen, the higher the amount of pixels.
The app is limited to odroid platform. I don't like if it is used from someone in the world somewhere on platform whatever. And because of the cpu load it is not at all for a battery powered smartphone or tablet.
The wallpaper app comes with no pre installed logo. To install a logo, a vector scaled image (.svg) must be present in a public folder like Download.
There are color settings for the background and for the drawing. In the svg like the one from Volvo, Mercedes or Renault I tried, the vectors are given with <path ...>. I paint the path with the given draw color. But if svg has an own color definition it is painted with this color. I have removed from Renault svg this part to have it colored by my app:

Code: Select all

<style type="text/css">
	.st0{fill-rule:evenodd;clip-rule:evenodd;fill:#231F20;}
</style>

The other settings are for step size X- and Y-direction every update and the update rate per second. This way it can be adjusted how fast the logo moves over the screen.
Next, if it is complicated to find the configuration screen for live wallpaper, this command at adb shell can be given, to open it:
am start -n com.android.wallpaper.livepicker/.LiveWallpaperActivity

MovingElementLiveWallpaper-v1.0.0.zip

(6.59 MiB) Downloaded 15 times

To install it with adb shell it is needed to give -t option:
adb install -t MovingElementLiveWallpaper-v1.0.0.apk

screen_volvo.png (54.99 KiB) Viewed 2690 times

[rooted]

Very nice, I love Volvo as well

[zyssai]

Good work mate
I will try to use it when all my stuff will be ready

[joerg]

Time to publicate my bad experience with Calk-Elec. Since months I try to get a 7" black frame touch screen to rebuild my Carputer for the new car. A ready one with LCD 1280x800 I ordered before at AliExpress was not functional and misaligned, so and I sent it back and received my money back. Then I ordered a 7" black frame touch panel without LCD at Chalk-Elec. When I received it, I tried it without to remove the protection foil. I found that a part at right side aprox. 15mm is dead, no touches. On the usb connection board there is one green LED. The Led dims a little down when touches are occur. On the dead area the LED stays shiny. I tried it with other computers, 2 different Windows and my Linux Host. Always the same. OK, I thought, maybe the firmware on the board is not correct, so I searched on their web page for a last version. I flashed it to the board, but always the same.
Well, I sent an email to them and got in contact with Dr. Ace Jeangle. He sent me a new firmware file, I flashed it, the same. He sent me another 4 different firmware files. He explained that as I answered that on the back side of the fpc print, there is no serial number, they can't know what would be the correct firmware of it. Ha.
Ok, I flashed all of them with the same result. I asked if they would replace it with a working touch panel, no answer anymore. Note that I paid $60.49 for product and shipping and more VAT and Fedex fee €16.61.
Since I reported that none of the 4 firmware are working I don't get any answer from Dr. Ace Jeangle.
Then I tried a lot by myself. I ordered some 6pole fpc bread board. I tried to connect it directly to the I2C port of my C4 and compiled the kernel with GT911 touch module and needed to find a valid device tree setting. As I couldn't get it work I tried it with an Arduino Nano board. I found some library for it and ported it to ATMega328P. When I tried and tried, at the end I found that I connected it wrong. Now with correct connection I got touch events reporting to serial usb port. I found that there is always the dead zone on the right. There are no interrupts generated in this zone.
With the knowledge of right connection I got it also work with at I2C of the C4! But always the same. I read and learned and tried to download different configurations to the GT911. But nothing helped. I found also that after power cycle the configuration always resets to former configuration. I am in doubt that my flashed configuration is accepted by the chip.
The configuration I read out after power cycle doesn't match the connected pins.
As of the photo can be seen that channels 0 to 11 of sensors are connected, channels 12 and 13 not. Also the driver channels are not all connected, channel 0 to 10 and 12 to 22 are connected, 11, 22 and 23 are not.
I am pretty sure that the configuration is not right for it. I don't have the Goodix Tool to design a new configuration.

photo_2023-05-18_14-00-20.jpg (249.41 KiB) Viewed 441 times

And the configuration buffer:

Code: Select all

Configbuffer:
0x8047: 0x5B
0x8048: 0x0
0x8049: 0x5
0x804A: 0x20
0x804B: 0x3
0x804C: 0x5
0x804D: 0xC
0x804E: 0x0
0x804F: 0x2
0x8050: 0x8
0x8051: 0x19
0x8052: 0xC
0x8053: 0x5F
0x8054: 0x4B
0x8055: 0x3
0x8056: 0x5
0x8057: 0x0
0x8058: 0x0
0x8059: 0x0
0x805A: 0x0
0x805B: 0x0
0x805C: 0x0
0x805D: 0x0
0x805E: 0x0
0x805F: 0x0
0x8060: 0x0
0x8061: 0x0
0x8062: 0x8C
0x8063: 0x28
0x8064: 0xC
0x8065: 0x38
0x8066: 0x36
0x8067: 0x29
0x8068: 0xB
0x8069: 0x0
0x806A: 0x0
0x806B: 0x2
0x806C: 0x0
0x806D: 0x3
0x806E: 0x2D
0x806F: 0x0
0x8070: 0x0
0x8071: 0x0
0x8072: 0x0
0x8073: 0x0
0x8074: 0x0
0x8075: 0x0
0x8076: 0x0
0x8077: 0x0
0x8078: 0x0
0x8079: 0x0
0x807A: 0x32
0x807B: 0x5A
0x807C: 0x94
0x807D: 0x5
0x807E: 0x2
0x807F: 0x8
0x8080: 0x0
0x8081: 0x0
0x8082: 0x5
0x8083: 0xD
0x8084: 0x1F
0x8085: 0xCD
0x8086: 0xD
0x8087: 0x21
0x8088: 0x95
0x8089: 0xE
0x808A: 0x24
0x808B: 0x5D
0x808C: 0xF
0x808D: 0x26
0x808E: 0x25
0x808F: 0x10
0x8090: 0x29
0x8091: 0x0
0x8092: 0x0
0x8093: 0x0
0x8094: 0x0
0x8095: 0x0
0x8096: 0x0
0x8097: 0x0
0x8098: 0x0
0x8099: 0x0
0x809A: 0x0
0x809B: 0x0
0x809C: 0x0
0x809D: 0x0
0x809E: 0x0
0x809F: 0x0
0x80A0: 0x0
0x80A1: 0x0
0x80A2: 0x0
0x80A3: 0x0
0x80A4: 0x0
0x80A5: 0x0
0x80A6: 0x0
0x80A7: 0x0
0x80A8: 0x0
0x80A9: 0x0
0x80AA: 0x0
0x80AB: 0x0
0x80AC: 0x0
0x80AD: 0x0
0x80AE: 0x0
0x80AF: 0x0
0x80B0: 0x0
0x80B1: 0x0
0x80B2: 0x0
0x80B3: 0x0
0x80B4: 0x0
0x80B5: 0x0
0x80B6: 0x0
0x80B7: 0x2
0x80B8: 0x4
0x80B9: 0x6
0x80BA: 0x8
0x80BB: 0xA
0x80BC: 0xC
0x80BD: 0xE
0x80BE: 0x10
0x80BF: 0x12
0x80C0: 0x14
0x80C1: 0x16
0x80C2: 0x18
0x80C3: 0xFF
0x80C4: 0xFF
0x80C5: 0x0
0x80C6: 0x0
0x80C7: 0x0
0x80C8: 0x0
0x80C9: 0x0
0x80CA: 0x0
0x80CB: 0x0
0x80CC: 0x0
0x80CD: 0x0
0x80CE: 0x0
0x80CF: 0x0
0x80D0: 0x0
0x80D1: 0x0
0x80D2: 0x0
0x80D3: 0x0
0x80D4: 0x0
0x80D5: 0x21
0x80D6: 0x20
0x80D7: 0x1F
0x80D8: 0x1E
0x80D9: 0x1D
0x80DA: 0x1C
0x80DB: 0x18
0x80DC: 0x16
0x80DD: 0x14
0x80DE: 0x13
0x80DF: 0x12
0x80E0: 0x10
0x80E1: 0xF
0x80E2: 0xC
0x80E3: 0xA
0x80E4: 0x8
0x80E5: 0x6
0x80E6: 0x4
0x80E7: 0x2
0x80E8: 0x0
0x80E9: 0xFF
0x80EA: 0xFF
0x80EB: 0xFF
0x80EC: 0xFF
0x80ED: 0xFF
0x80EE: 0xFF
0x80EF: 0x0
0x80F0: 0x0
0x80F1: 0x0
0x80F2: 0x0
0x80F3: 0x0
0x80F4: 0x0
0x80F5: 0x0
0x80F6: 0x0
0x80F7: 0x0
0x80F8: 0x0
0x80F9: 0x0
0x80FA: 0x0
0x80FB: 0x0
0x80FC: 0x0
0x80FD: 0x0
0x80FE: 0x0
0x80FF: 0xEA
0x8100: 0x0

Now I am without idea how to continue...
It seems that I have lost > 70 Euros.
Dr. Ace Jeangle from Chalc-Elec does not answer anymore.
It seem that he leaves his customers without support or refund.

[edit]
BTW. From their website:
Our main goal is to support electronic enthusiasts with their hobby electronic projects based on BeagleBoard, PandaBoard, BeagleBone, Raspberry Pi etc.

[L67GS]

Is it too late to leave a review on AliExpress? That might motivate the good Doctor.

[zyssai]

So sorry to hear that, you really have no luck with your screens.
I don't know how I can help you, you probably can buy a cheap usb touch panel?

[joerg]

Is it too late to leave a review on AliExpress? That might motivate the good Doctor.

No, they don't sell over AliExpress. This was the former screen I bought from AliExpress. Chalc-Elec sells over their own webpage and they are from Malaysia.

[joerg]

So sorry to hear that, you really have no luck with your screens.
I don't know how I can help you, you probably can buy a cheap usb touch panel?

Sadly my demands are special. My LCD is 7" 1280x800. It has different visible area as an 7" 1024x600. So, it's hard to find the correct one. I saw on Alibaba some producers that can make on demand, but my experience with those producers are also not good. I tried last days to buy two 15.6" usb touch panels, i already paid, and then began the discussion. At the end they wanted to have 20 dollars more for shipment as I paid over the shop. I canceled the order yesterday.

[mctom]

Sorry to hear that you had such a bad luck with these displays.
I wouldn't order a custom made display on Alibaba. Nobody takes seriously orders on one piece, unless you make them think that you represent a company and wish to buy a sample, then it's a different story.

Since you have impressive display hacking skills (seriously I'm very impressed!), perhaps you could buy a device that has a display built in already? Maybe a tablet? As a bonus, tablet's firmware would tell you exactly what driver it uses.
For example, Lenovo A7 tablet, used, broken but with a display in good condition may cost €10.
That's how I got three 800x600 eInk panels.

Also, I quickly googled Polish shops:
https://kamami.pl/en/electronics/232846 ... currency=2

[joerg]

Thank you again for a link to a interesting shop. But what I need they don't have.
BTW, I have installed back the old touch panel open frame type to the LCD. I've ordered some 9H glass in the format I need. I made yesterday some test with a smaller 9H glass to paint it with black spray from back side. It's looking well. So I am in hope to produce my own black frame cover glass for this old touch panel.

photo_2023-05-23_20-30-31.jpg (230.6 KiB) Viewed 423 times

[joerg]

I've done it! Made my own black frame cover. Build from two glass foils, black car deco stripes (tape), glue UV-LOCA (flexible transparent glue UV hardened).
Fixed the black stripes on the first glass foil, then fixed the second glass foil on it with some grams of UV-LOCA. But it was very hard to remove all air bubbles. The top foil always shifted away. At the end I put it 30 minutes into a UV case I have >30 Years (for pcb photo exposure). I used 30 minutes, because the UV-LOCA I have also about 3 years and it works, also it's years over its expiry date.
But I am not sure if I stay with it, as it doesn't look very professional.

photo_2023-05-25_17-35-23.jpg (159.79 KiB) Viewed 261 times

photo_2023-05-25_17-35-49.jpg (149.09 KiB) Viewed 261 times

I have found this on 8" Black Frame Capacitive Touch Display on Waveshare. I am about to decide to buy it:
https://www.waveshare.com/8DP-CAPLCD.htm

[zyssai]

Wonderful work mate!
I also played with uv loca to replace glass of an Apple iWatch.
Hard work, the most difficult part is to prevent any bubble to appears and ruin the game.






(Sorry a bit off-topic)

[rooted]

Is this bonding the glass to the LCD?

[zyssai]

Is this bonding the glass to the LCD?

Yes, I think the only way to disassemble such a glass and a LCD (or touchscreen panel depending on what you wanna do) is to insert a thin metal wire like you see in these pictures, and to gently slide it left and right. Hot air helps.




I think the process is similar with an LCD screen like the one joerg uses.