This hat is designed to work together with OpenAuto Pro and deliver some functionality which makes integrating OpenAuto into your car easier.
I'm not an electronics professional and this board is currently work in progress. If somebody is willing to do a indepth review with me I would be very glad. Reach out to me on twitter @MoJo2600.
- Integrated 5A Power Supply
- Wide range power input (+7.5V to +40V)
- On-/Off circuit with ignition sensing
- 2 Digital inputs for e.g. reverse signal
- I2S sound
- RTC clock
- CSI to HDMI adapters to connect a display and camera
- I2C bus availabe on the display connector for a light sensor
- Designed to fit exactly onto a Geekworm x825 SSD V1 (Not tested with V2 but should fit)
the following pins are used on the pi.
| Connection | Pin |
|---|---|
| I2C | BCM23 |
| I2C | BCM24 |
| REVERSE | BCM8 |
| LIGHT | BCM25 |
| PI UP | BCM23 |
| SHUTDOWN | BCM24 |
| I2S DAC MUTE | BCM16 |
| I2S DAC BITCLK | BCM18 |
| I2S DAC LRCLK | BCM19 |
| I2S DAC DATAIN | BCM21 |
Set up the device before you add the header to the raspberry pi. The device will constantly reboot if the Start / Stop script is not installed. An alternative is to bridge the 3.3V pin from the raspberry pi to BCM23.
Copy scripts/startstop.sh to the openauto device.
sudo bash startstop.sh
Make sure the battery has contact to the pad on the minus size. Mine had not and I added a little bit of solder to the pad to make contact.
# select pcf85063
This script will open raspivid and show the picture of the rear camera.
Copy all files to the raspberry pi and start the setup
./setup.sh
My brightness script utilizes the TSL2561 ambient light sensor. The script implements a recommendation from analog devices https://www.analog.com/en/design-notes/a-simple-implementation-of-lcd-brightness-control-using-the-max44009-ambientlight-sensor.html
Copy all files to the raspberry pi and start the setup
./setup.sh
The current audio circuit is not really usable. The output is very noisy und the signal is too low to usw it effectively. If you want to try i t you can use the following settings.
Add the overlays to /boot/config.txt
dtoverlay=hifiberry-dac
dtoverlay=i2s-mmap
After a reboot the sound should be working. Expect a line level output. If the volume is set to high, there will be clipping.
I had to install the bluetooth firmware for my broadcom bluetooth dongle from this repository https://github.com/winterheart/broadcom-bt-firmware.
The error in dmesg was:
bluetooth hci1: Direct firmware load for brcm/BCM20702A1-0a5c-21e8 failed with error -2
Bluetooth: hci1: BCM: Patch brcm/BCM20702A1-0a5c-21e8 not found
The installation was easy:
wget https://github.com/winterheart/broadcom-bt-firmware/raw/master/brcm/BCM20702A1-0a5c-21e8.hcd
sudo cp *.hcd /lib/firmware/brcm/
Here is a picture of prototype V1 with a Mouseberry power supply.
Due to the fact we are not providing a product in the legal sense, we are also not providing any warranty in any aspect.