TBM 4.x, on the Bike!

TBM 4.x is on the bike and communicating with the Alltrax, the speed sensor is working. I need some velcro tape and dry weather to do some road testing.

Adding some capacitors to enable data saves will be next, along with some buttons to enable programming/changing modes.


I'm investigating next steps in this project with an advisory panel to see to proceed - perhaps a full product, perhaps a kit and plans. Getting a PCB spun and maybe design an LCD would be cool too.

Add your suggestions/comments/votes below!

TBM 4.x, Demo Packaging

After learning some harsh lessons in electronics packaging, I have a demo unit that should withstand being mounted in the bike.

The big thing that cannot be underestimated is STRAIN RELIEF between the board
and components. PCB "headers" and "header-sockets" are my new best friend.

Some spacers are necessary between the boards. Next time I will mount the
Boarduino upside down, or simply build it into the full board if I get PCBs made.

And between the boards. Next time the header socket goes ON the LCD, header on the PCB, as making "solder bridges" to the socket was tough.

Time to get this bad boy in the bike for some testing. I'll be shopping for PCB fabs too.

TBM 4.X, Boarduino Edition

My 2 "Boarduino" kits arrived and I soldiered them up, wired up the LCD and serial TTL converter (finally arrived), pushed up the code and after some tweaking, it worked!

Not quite sure its the correct form factor (see lower left) - seems focused on using a breadboard,
but with headers reversed it might work well.

AGM Performance Decay

Remember the almost 17 mile adventure ride to Inspiration Point and back? I ended up on an adventure today when attempting to run an errand across town and back, 6 miles in and climbing a hill, Tronbike 1.2.8 just stopped, even the contactor couldn't keep going.

I was less than a mile from the destination at a cycling friends house to pick up tires, on a road easily climbed by a normal bicycle, so I walked there and back to give the bike a rest (let the batteries re-balance a bit), before limping - like barely limping - to his driveway for an extension cord. The voltage drop on the left is due to my own hot-rodding up the hills, the computer was turned off for serious limping efforts.

An hour later I was off again, the voltage drop considerably less than before (right side of graph).

The lesson is that battery decay even happens to me, and that I should stress things to the max more often in a safer way. My power left meter indicated I had 78% of my pack left of my 3300 KW-hr - I need to check the calculations but that seems way off. The whole voltage drop effect might be due to the batteries at the edge of my chain going out first - my usual commute I ride 2-4 miles, park all day and go home on flattish terrain.

The fix? #1 Calibrate the gauge, #2 check the batteries individually, #3 time for a new battery solution.