VOLVO+ Development Story (8), A-SS function definition

After completing the remote tailgate control function, then I wanted to develop auto start-stop (A-SS) default-off feature. I would like to discuss this feature first




Many people don't like A-SS it drained more battery power undoubtedly, used starting motor more times. Many people stopped the feature as engine on. I like this feature really, especially some traffic light with 90 seconds. However, as queuing to turn left/right, the A-SS start latency was sometimes quite annoying

I consulted many people, roughly 3 views to this feature
  1. Always enable A-SS
  2. Always disable A-SS
  3. Default A-SS off, and enable A-SS on-demand
The Russia developer's product remember the A-SS state as engine off, and remains the status in the next engine start. The logic is fine to the 1st/2nd, but not good for the 3rd one: I shall *remember* to disable A-SS before engine off, which adds more burden


Finally, I defined A-SS OFF feature by default. Car owner doesn't remember any rule. As I recalled this, the conclusion is quite simple, but it takes time to get the result

Comments

Post a Comment

Popular posts from this blog

OBD-II and ELM327 (1)

Image
I bought a Volvo XC60 2017, and the car had an OBD-II port. I always feel the port is inviting me to do some hacking. I had power supply, oscilloscope, soldering equipment, multi-meter. I can read English, and had some embedded system development experience, but no hacking car ever. Maybe with some study, I can learn to do that My adventure starts with ELM327, the equipment is quite cheap. I want to talk pro/con of the cheap China ELM327 unit, and when you will feel disappointed to it ELM327 is basically a Microchip PIC18F2480 with customized FW, which supports various OBD protocol. Picture below is from its datasheet Left-upper corner, MCP2551 is the CAN transceiver It communicates to car by CANL/CANH signals It outputs CAN signal to PIC18F2480 (ELM327) (PIN1/4) PIC18F2480 (ELM327) It accepts the output signal from CAN transceiver The internal CAN controller send/receive from CAN bus It had UART interface in PIN17/18 Option1: FTDI UART to USB interface Conne
Read more

OBD-II and ELM327 (3), try to decode CAN package recorded by ELM327

Image
Volvo XC60 2017 doesn't offer the capability of closing tailgate by remote control. I have to press the button in the tailgate (see below) to hand. That's probably because of security reason, but I feel so stupid. M assumption is, the button sends some message to CAN bus. If I can sniffer the signal, I can close the tailgate remotely Challenge Accept !! I connect the ELM327 with my XC60, and successfully read VIN code . Then I tried ATMA (Monitor All) command to sniffer CAN bus... Then... nothing happened !! What the fuck ?! So now I can tell you when the cheap ELM327 makes you disappointed In complete AT command Because Torque App doesn't use ATMA command, so the cloned ELM327 don't offer such capability Poor bluetooth connectivity As sending ATRV command, sometimes I got incomplete response. I guess that's because bluetooth module doesn't work well Even the cheap ELM327 dongle offers ATMA capability, the data rate is far exceeding the blue
Read more

OBD-II and ELM327 (2), the underlying interface of ELM327

Image
Go to Google play and search keyword of "ELM327 Terminal", all of them were similar, you can just pick arbitrary of one. If you really had some difficult of selection, this one  looks beautiful and just updated recently After connecting the tool with ELM327 and car, type "0902" in the tool to read the VIN code . These PIDs (0902) were industrial standard , and all cars shall implement it. Here's some useful PIDs. That's why HUD (head up display) can connect to all brands of cars with OBD2 connector 01 0D: car speed 01 0C: engine RPM Here's the 0902 query response of my car in the APP. If interested, decode it :-) 7E8 08 01 14 49 02 01 59 56 41 7E8 08 21 44 5A 41 38 42 44 48 7E8 08 22 32 30 37 36 36 38 32 A lot of people read CAN bus by Torque, but only few people read the ELM327's capability document. Check out ELM327 website and download their AT command list , that's all the capability it had. It had different capability
Read more