CAN budget calculations

can-budget.py

cid = 28
# cid = 11

framebits = { # including average number of stuff bits
    11: [47, 55, 63, 71, 79, 87, 95, 103, 111],
    28: [65, 73, 81, 89, 97, 105, 113, 121, 129]
}

service = [] # name, update rate, bytes, nb. nodes
service.append(("dyn_ctrl", 400, 8, 2+3*2)) # float32 pos, float16 vel, float16 torque, 2 wheels + 3 per arm
service.append(("pos_fb (odom)", 400, 2, 2)) # uint16 coder cnt
service.append(("pos_fb", 100, 2, 6)) # uint16 coder cnt
service.append(("servoctrl", 50, 4, 16)) # float32 pos
service.append(("servoctrl", 100, 4, 16)) # float32 pos
service.append(("dist_sens", 50, 2, 8))
# service.append(("pid_calib", 5000, 4, 1)) # float16 err, float16 ctr


print("using {}bit can id".format(cid))

budget = 0
for s in service:
    cost = s[1] * framebits[cid][s[2]] * s[3]
    print("{:15}: {:4}Hz, {}byte, {:2} nodes, {}%".format(*(s+(cost/10000,))))
    budget += cost

print()
print("budget: {} / 1000000 = {}%".format(budget, budget/10000))