Modularity, I like that....
I would like to add this: think outside the box and don’t put everything in one box.
I apologize if the ideas I present here have already been discussed, but I glaze over badly when trying to catch-up on a long thread. (And yet here I am making it much longer and harder to read. I was learning google sketchup last night but I’m still too slow and too impatient.)
I’ve been pondering my next build from a systems design standpoint, and I want to do everything I can for a clean looking, low maintenance install. It is not convenient to connect every wire on a bike to one box. I don’t want to use another Chinese controller. (I saw the inside of mine, it isn’t pretty)
Personally, I would like a handle bar mounted LCD to display: speed, maxspeed, avgspeed, actual time, trip time, odometer, trip odometer, amps, maxamps, volts, minvolts, watt-hrs, Wh/km, Wh/mi, battcycles, avgWh/mi, etc, and a keypad to allow me to set the controller parameters and the throttle response, cruise control etc. and to control my lights. I don’t want to use a separate programmer for the control setup, and I don’t want any other devices mounted on my handle bars.
A display mounted on the handle bars would provide a convenient junction box to connect the brake levers, throttle, headlamp, blinkie, front turn signals, and turn signal switch. The wires would be short and only the 12V, ground and comms wires would run off the handle bars to the rear.
(Kingfish: having just completed your light setup you can maybe appreciate where I am coming from, a major drawback with ebikes are the large bundles of wire flexing every time the handlebars are turned). (By the way, were my suggestions on the converter thread helpful?)
The display module would have:
-a backlit LCD – I don’t know if graphics would be possible, or if that pushes the processor to a whole other level, but it would be nice. Actually it could make a huge difference in bling factor, and readability.
-a simple, small linear regulator for the processor 5 volt supply.
-protected-driver 12 volt outputs for lamps, or current limited LED supplies, either way there are lots of chips and modules available for either, both could be an option on the pcb.
https://ec.irf.com/v6/en/US/adirect/ir?cmd=eneNavigation&No=0&N=0+4294835973&numRecs=99
http://www.dealextreme.com/details.dx/sku.13557
(I apologize for placing a deal extreme link in your thread Kingfish)
-a keypad that has actual mechanical switches, or at least a membrane with good tactile feedback. (I wear gloves whenever I ride)
-The display module must be absolutely waterproof. (the last two items are almost mutually exclusive aren’t they?)
-I would also like to shoe horn in a 433 Mhz transmitter and antenna with a tilt sensor into my display.
The small three wire cable from the display would connect to another box mounted to my seat post.
This box would be designed as a light bar with the rear blinkie and turn signals on the back surface and the heatsink on the front, the only connections to this box would be the aforementioned comms/power cable to the display; plus wires for the halls, phase wires, and the battery wires, all exiting the bottom. (I see you’ve been considering turn signals too Kingfish)
Inside the box would be:
- the DC-DC converter, 12 volts out should be all that’s necessary,
- a small linear regulator for the processors,
- current limited supplies for the LEDs.
- a processor for comms and the battery monitor and running the rear signal lights and talking to the motor control processor.
- motor processor and FET driver board,
- FET board (I’m liking LFP’s surface mount suggestion, we all build our bikes in the kitchen, why not bake our FET boards there too?),
- a 75 watt 12 volt output for heated clothing. (not many people would need this).
I’m thinking an aluminum extrusion would be good for this box, and a design that allowed removing the light panel to provide access to everything without disturbing any wires or heat sink connections would be a priority.
Since the light bar won’t be all that wide it would be nice if the turn signals were moving arrows <<< (*) >>>
I don’t expect that anyone will share the exact same vision as me for the system design. One benefit of an open source project is that others can modify the design to suit their needs. My intention is to help stimulate the discussion and encourage a flexible modular design.
Of course there are many variations possible, like moving the motor control board to yet another box, or dropping the turn signals, maybe use part of the bike as a heatsink. Where should the main power switch and key switch be mounted, front or rear? Could the turn signal switch reside on the side of the display or would restricting the module mounting location to one side of the handle bars be a problem? Maybe the display graphics/text could rotate so you could flip it to mount on either side of the bars, or even turn it 90 degrees?