Modern vehicles are beginning to use PWM to control the output of their circuits for the same reasons Motobrain does this. This is great, but it creates an issue if you want to use the status of the OEM circuit that is using PWM to trigger a Motobrain output. A user brought this to my attention and we were able to get it into the coming hardware revision of Motobrain. You can now create a trigger that looks for a PWM signal at an input and will allow you to define an arbitrary action just as you could with a standard voltage trigger before.
The next generation Motobrain hardware will draw 6.4mA in standby mode. It does not scan it’s inputs for triggers in this mode. It only waits for the key signal to turn on or the Bluetooth to connect.
How it works in practice is that when the key signal is off and no outputs are on we turn off all non essential hardware and slow the main clock chip way down. then every 8 seconds we turn it back on and look for a Bluetooth connection request. If we see one, we turn the device back on and continue where we left off.
The image below shows the current draw over time where one mV equals one mA. My integration of those values gave a weighted average of 6.4mA.
Building just the smart half of Motobrain, what I call the “brain board”, requires 220 surface mounted components (40 different types) with 900 individual solder joints. I will manually place all the parts on the PCB and then “reflow solder” them to the PCB. It is an arduous task to be sure. Conveniently, I believe the next one I build next will be the last one I have to build. If this new PCB works as expected, I expect the rest to be manufactured by robots. Let’s hope it works out! The one below had a PCB manufacturing error which required me to install a “bodge wire”. Can you find it?
In the photo below you can see all the parts counted and taped to two sheets of paper. There is also a built brain board (in purple), a pile of new green unassembled brain boards, and two different “power boards” and piles of their unassembled PCBs. The different power boards define the alternative product features and shape but both use the same brain board.
We have a new high current PCB manufacturer and we are doing our first burn in test with their boards. We are currently driving 100A through the Motobrain to see how their boards endure the abuse. These boards use new MOSFETs (the solid state switches) which are larger than the first version of Motobrain. The boards themselves have 20 ounce copper foil (an indication of thickness) which affords them a measured 840µΩ of impedance across the PCB. That means the at the PCB itself only consumes 840mW (milliwatts) at 100A. After an hour at 100A the PCB is locked in at 55C (ambient is 24C). Not too shabby.
These boards have a slightly different layout to the first generation version of Motobrain. Users said they would prefer if all the wires could leave in one direction. We are happy to oblige.
We’ve been posting about updating Motobrain with CANBus and LINBus capability on Facebook for a little while now. Here is the first example of that triggering capability in action. Here we show a new Motobrain prototype monitoring the coolant temperature signal from a simulator and adjusting the PWM of a output to compensate for that input. This capability should be available around first quarter of 2016.