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#TennisBeast edited this page May 11, 2022 · 1 revision

First of all, for the Xaviers, a few commands need to be run to enable the CAN Bus hardware using busybox. They are as follows:

sudo apt-get install busybox

sudo busybox devmem 0x0c303000 32 0x0000C400

sudo busybox devmem 0x0c303008 32 0x0000C458

sudo busybox devmem 0x0c303010 32 0x0000C400

sudo busybox devmem 0x0c303018 32 0x0000C458

These commands need to be run just once for each Xavier, and never on the TX2s.

For any CAN communication to work with both the TX2 and Xavier, the following commands must be executed after each shutdown/power on:

sudo modprobe can_raw

sudo modprobe mttcan

sudo ip link set can0 type can bitrate 250000

sudo ip link set up can0

Currently for our purposes, we only need to use one CAN port, so we can just set up can0. The TX2 has two CAN ports, so to initialize the second one (which once again is not necessary for us) execute the following as well:

sudo ip link set can1 type can bitrate 250000

sudo ip link set up can1

Now for the battery stuff

Every 3 seconds a "heartbeat" of 5 messages is sent out by each battery. Here is an example:

can0 5FF [8] 20 81 21 01 00 00 00 38

can0 5FF [8] 30 01 38 64 DC 05 E8 03

can0 5FF [8] 31 01 4D CF 01 00 00 00

can0 5FF [8] 32 01 5F 0B 73 0B 72 0B

can0 5FF [8] 33 01 00 00 00 00 00 00

For each message, the first value is D0, then D1, and so on until D7.

D0, or data0 contains the message identifier, 20, and 30-33. In the code file, these data values are converted to 32, 48-51.

In the FlexibleBatteryCan class,

  • Message 20/32 is referred to as soc_msg.

  • Message 30/48 is referred to as soh_msg.

  • Message 31/49 is referred to as cyclecount_msg.

  • Message 32/50 is referred to as temp_msg.

  • Message 33/51 is referred to as bytecurrent_msg.

List of the data contained in each message: Notes: - For values that are just numbers, they are always that number and are used for internal battery communication - We only use Temp 1

20: 81, 21, Battery Number, Alarm1, Alarm2, Status, SOC

30: Battery Number, SOC, SOH, Max Discharge Current (D4 and D5), Max Regen Current (D6 and D7)

31: Battery Number, Pack Voltage (D2 and D3), Cycle Count (D4 and D5), Not Used, Not Used

32: Battery Number, Temp 1 (D2 and D3), Temp 2 (D4 and D5), Temp 3 (D6 and D7)

33: Battery Number, Low byte current 1, Low byte current 2, High byte current 1, High byte current 2, Not Used, Not Used

Examples:

Deconstruction of 30

SOC (state of charge): D2

D2: 38

Hex value: 38

Decimal value: 56

Note: On Page 8, says the following

  • Range: 0-100, %of remaining capacity
  • So: 56%

Max Discharge Current: D4 and D5

D4: DC D5: 05

Hex value: 05DC

Decimal value: 1500

Note: On Page 5, says to do the following:

  • 1500/10 = 150A
  • Max Regen Current
  • D6: E8 D6: 03
  • Hex value: 03E8
  • Decimal value: 1000
    • Note: On Page 5, says to do the following:
    • 1000/10 = 100A

Deconstruction of 32

Temp 1: D2 and D3

D2: 5F D3: 0B

Hex value: 0B5F

Decimal value: 2911

Note: On Page 8, says to do the following:

  • Range: -40C to 120C
  • (Value-2731)/10 = tempC
  • So:
  • (2911-2731)/10 = 18 Degrees C = 64.4 Degrees F

Info of the battery we used (From manual - https://ceb8596f236225acd007-8e95328c173a04ed694af83ee4e24c15.ssl.cf5.rackcdn.com/docs/product/InsightBatteryManual_040121_210401_115955.pdf)

Model: 48V030-GC2

Nominal Voltage: 51.2V

30 Ah

1.536kWh

128Wh/kg

Continuous Discharge Current: 100A

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