This evening has been full of research. I was looking at how to get different devices to communicate together with an Arduino or two monitoring temperature, voltage, speed, and so on. I then started looking to see if Arduino could somehow emulate a cars OBD2 drive so I could pretend I had a modern car that reported on what was going on under the hood
One thing led to another and it was a pretty nice eureka moment coming to the understanding of what CAN Bus and OBD2 (OBDII) actually were – and that I could just use CAN itself to communicate to each Arduino device on its network, and expose that on the standard adapter that everyone plugs into.
Set into car
I recall seeing things in the head unit regarding CAN bus. I started looking into how to resolve the “Set into car” button where it would tell me “No original vehicle setting function”. I went into Factory Settings and then looked at the first item – protocol settings. From within, I saw the title of the app was actually “CAN set”. I was onto something!
Quite a few of the brands were unfamiliar. Raise, Hiworld, BNR, XBS, XINPU, Daojun, Oudi, Ruishengwei, HCY, Hechi, Ansheng, Bagu, Luzheng, Anyuan, NFCK, LH, CML … okay, all brands were unfamiliar. I’m assuming some of these are the Pronunciations of Chinese words. Perhaps Oudi is actually Audi, or maybe these are different protocols that sit on top of CAN bus.
I started poking around and saw “Raise” had an entry for “Electric car”. I selected that and went with the only option JRYG-M2 which had a can ID of 1034001.
I was able to go back to the car settings and click “Set into car”. Sure enough, it went ahead and showed me a new screen for an electric car.
I had quite a few icons that led me to see temperatures, voltages, torque, current, etc. It was all blank – but it was something. It was waiting for communications to be sent over the CAN bus.
Now we are at the last part – where are the wires to hook up the CAN bus? I think this is where the steering wheel controls for KEY1 and KEY2 come into play. I think without CAN, these two wires are treated the same, simply for generic SWC with a 0-5k resistance to ground. I suspect that KEY 1 and KEY 2 are CAN High and CAN Low wires.
I’m under the impression that I just need to look at the OBD2 format of a few setting sand test sending it over the CAN bus to verify it the device starts picking it up. Once that part is done – actually acquiring the data is a fairly heavy task as well.
Playing with CAN is another project on its own. I think eventually I’ll look into playing with CAN modules later. I’ve seen quite a few gadgets to hook up Arduino’s over the network using an TJA1050 CAN controller interface chip. One model I’ve seen is LDTR-WG0210, compatible with the ISO 11989 standard.
I just received a reply from the seller with a manual for A2222 Android Products Operation Manual: Android Interface Instruction. It’s much better than what came with the device. I’ve worked out quite a bit of it on my own already, but it’s nice to see a confirmation that I went in the right direction. This is what they say about features related to canbus:
Support steering wheel control (don’t support cars need a canbus)
They also replied directly this is a universal double din car stereo, and that if my car needs a canbus, it will not support the steering wheel control.
I think I’m out of luck. I was hoping I could choose to either have those two KEY wires for either SWC or CAN bus – like you could only choose between the two, but used SWC by default until the canbus settings were setup. It would have made more sense of why the same resistance on both of the KEY wires couldn’t be mapped to two separate steering wheel controls.
I could go ahead and try to experiment later with canbus just to make sure, but by that time, I may just go with another radio that does support it.
I feel this is a bit absurd, but I figured out how to wire the 8-Track car radio into an Android head unit for the CitiCar. It’s “old vs new” where the two radios work together in epic proportions.
The 8-Track car radio can pickup both AM and FM, where the Android tablet is only compatible with FM stations. I like the older way of doing it instead of the digital radio app that they provide on the tablet.
Made in China
The Android tablet is strait out of China. Going under the hood, I was running into odd phrases and in some cases, a full screen of Chinese writing without an ounce of English.
I had to uninstall apps such as one that had a logo of iFLY that kept changing my settings to use a Chinese keyboard at each boot-up. I still need to go over all apps to verify how much I trust them.
As a programmer, there were a few things of note that I did when digging around in the app. Here are a few of the default passwords I gathered, and things I did to get more access to the system.
Android Settings About vehicular platform Click build number 9 times
OEM unlocking: On
Engineering test debugging
Bluetooth: Car BT
Accessing the Android system for configuration
I learned quite a bit about wiring with most modern cars today. The CitiCar itself does not have a radio. It is often displayed as an option that you can have added onto the base models price.
Being inexperienced with wiring a car radio, I was confused when I saw a bunch of wires, where only some of them were labeled, and even then – the labels didn’t make much sense to me.
I couldn’t even power the device on when I hooked it up. I saw it draw power for about minute, followed by a trickle. I learned that the thin red wire is wired to the key so that the device powers on when you turn the key to the accessory position.
I found a ton of videos online describing the standard colors for radio speakers, illumination, amp, antenna, and battery power. I still had some trouble with other wires. Here is a list of information I have learned.
First, I’m assuming that it needs a 25 amp fuse for both the speakers and the device/GPS/camera. The four speakers outputs are rated for 45 watts each, for a total of 15 amps on a 12 volt system. The device itself has its own 10 amp fuse plugged into the back.
25 Amp Fuse
Headlights or Dimmer Switch
Green + Stripe
Steering Wheel Control 0-5k Ohm
Steering Wheel Control 0-5k Ohm
Wires on a 12 volt car radio
Steering Wheel Controls
I’m not quite sure if it was the most fun, but it was the most interesting experience I had trying to figure out how the key wires worked. These are for your universal steering wheel controls (SWC). I learned that it’s a very simple system that looks at a resistance value up to 5k Ohms between either “key” wire and the ground wire, which triggers the device to execute a command mapped to a specific resistance (or close to it).
After playing around with various resistors, I found the device was able to determine the difference between the following:
SWC Resistance Sensitivity
I gave up by time I got to 150 as it seemed as if it could tell the difference between all of the last few resistors. The lower differences in resistance are the hardest for it to determine. At minimum, it is advised to step at least 20 ohms between each of your control values.
I may look into making a 3D printed device sometime to control the device, or buy a generic wireless steering wheel add-on that can be strapped onto the CitiCar steering wheel.
Of special note is that the two key wires appear to have the same behavior. Putting the same resistor value on both wires, the system will react the same way. My understanding is that this second wire is to allow passengers in the vehicle have control over some of the radios functionality as well.
8-Track Audio to RCA
I picked up an adapter with an RCA Male Plug on one end, and a screw terminal on the other. I was able to connect some wires from the 8-Track into the screw terminals. Then I simply plugged in the RCA jack into one of the RCA female plugs on the Android tablet to be available as an audio input device.
I’m still waiting for my remote control cable for a round Kodak projector 5 pin male plug to insert into the 8-Track radios plug. It will be easier to take the radio out of the car for maintenance in the future.
I purchased a pair speakers a few years back when I built a bar-top arcade. I went ahead and found the same speakers and purchased two sets for the CitiCar. I don’t know where I’ll put them just yet.
The last part of the equation was to hook up the speakers. The quality was much better than my test speaker. They are adequate for the car itself. The media tablet only puts out 45 watts to each speaker. 180 watts is more than enough to handle the power in such a small space.
I customized the display to show the Sebring Vanguard logo from my CitiCars hubcap during boot-up. After much troubleshooting, I found that I needed to use a 1024×600 pixel bitmap using a color depth of 24 bits. I used the same image for my wallpaper as a PNG file.
You can also set the boot animation. I’m often running into a wall trying to set it up. I’ve just recently got something working.
I’ve made a file that conforms to the bootanimation format. The latest thing that I did seems to have fixed the problem. I created a folder path to “/oem/media/bootanimation.zip”. I then went into the logo animation settings to select it. I’m a bit confused over it, but hey – progress. It may also be due to having the device in developer mode as well.
The device itself seems to be an unmarked/unbranded item. The plain brown cardboard box itself is marked as “Made in China” FCC CE and recyclable logos on opposite sides. It has no other details except a small label A2628KT on the top. Mucking about under the hood, I found a few things of interest, mostly regarding version numbers. The device itself thinks everything is up to date.
November 5, 2017
3.18.22 gangll@zx-PowerEdge-R730 #5 Thu Oct 17 10:26:20 CST 2019
Version information behind
Double Din Car Radio GPS Navigation Android Head Unit 7″ HD Touch Screen Indash Car Stereo Support Dual USB, AUX in, Bluetooth, WiFi, FM, Mirror Link with Rear Camera (2G+32G)
讯飞输入法 (iFLY App)
8-TRACK AM Vintage car audio RADIO original
Joe Knows Electronics 1/4W 1% 86 Value 860 Piece Resistor Kit
MCIGICM 10pcs Breadboard 830 Point Solderless Prototype PCB Board Kit Protoboard MB-102 for Arduino DIY Electronics kit
WGCD 20 PCS Phono RCA Male Plug to AV Screw Terminal Plug Connector Audio Video Adapter
Remote Control Cable 5 Pin Male (Round/Kodak) Cutoff 5 Wires 22 Gauge 12 ft
Universal Car DVD GPS Player Wireless Remote Controller, Steering Wheel Remote Control Button for Car Navigation DVD / 2 din Radio Bluetooth Steering Control
Kalevel 120pcs Breadboards Jumper Wires Male to Female Jumper Wires Male to Male Jumper Wires Female to Female Jumper Wires Kit Long Ribbon Cable 20cm (m-m, f-f, m-f)
KAIWEETS 10PCS Electrical Alligator Clips with Wires Test Leads Sets Soldered and Stamping Jumper Wires for Circuit Connection/Experiment, 21 inches 5 Colors (10 PCS)
Peter Frampton Music
I got “Car Settings” to do something. I’m beginning to think that KEY 1 and KEY 2 should be connected to the CAN bus. Here is how to make car settings show a screen for your specific car (If you had a Raise Electric Car JRYG-M2)
Car Settings \ Factory Settings  \ Protocol Settings \ Raise \ Electric Car \ JRYG-M2 (can ID 1034001)