I'll try to keep this short and its been awhile since I have posted my mods, so go easy on me
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The mi7 ti has a decent UI as is, so the reason I modded the light was to give it more current. 700 lumen's just isn't enough.
This is the Mi7 factory board.
I tried modding the original board. It uses a CN5711 to control the current through a sense resistor. http://www.consonance-elec.com/pdf/datasheet/DSE-CN5711.pdf
Best I can tell it has no pwm so it accomplish modes by varying the sense resistor. Which in the pic above on the right you can see the bank of resistors that all run back to a mcu at different pins on the switch side of the board. I changed several of the resistors but never gained any current in high. I could change low or med but not high. I think the mcu controls which sense resistor it uses back to ground on different pins to change modes(current).
It maybe using two in parallel for certain modes, I could never get it figured out because the resistor values never worked out to be the correct value in the datasheet for the output current. The current would never get above 1.5 amps. Datasheet says that it typical can run about 1.9 amps before the protection kicks in. I give up on this idea. I'll use a different driver.
I first used a 105c comfychair style FET mode with one 7135 left on, running JonnyC star FW (driver on the right). Using another stripped (unknown) board to be the slave (battery connection) and 105c as master, soldered it on at a 90 to mount the switch on the stripped back side, the wiring to make that work was a pain. It worked great but I couldn't lock the light out. If you unscrew the tail it will come a part before the connection is broke. So it had to be done in the FW which there was none for the attiny13a. I wasn't going to carry this little pocket rocket around unless I had some kind of lock out. So I had to choose a different driver. Since NarsilM is so popular I'll try a driver that can run it. I Purchased a few BLF X6 boards with the attiny25 from banggood. Purchased 10 attiny85's from digikey and a few small similar (Mi7 driver) switches while I was at it.
Hot aired the attiny25 off and bent the legs in on the attiny85 and reflowed to the X6 board. Loaded up Tom_E NarsilMQ8.hex. Used a stripped east92 board and cut it half with a few cut outs for clearance of the mcu. Soldered the half board on at a 90 and mounted and wired the switch on in a calculated position using the original Mi7 board for measurements.
Took a little filing here and there to get it to fit but I had to grind down the shelf in the head of the light so there was clearance for the attiny85. I used the Proxxon IBS/E and a carbide end mill to grind the Titanium.
You can see in the pic the two channels the original driver slid down into which I guess helps hold the switch in place. Wired up the led and put everything back together. Took a little tweaking to get the switch distance to button in the right place, to get a good switch response with no play.
Hello 2 flashes, Narsil up and running.
Using a Efest (purple) 650mah battery it draws 3.7 amps. The best part is I can now lock the light out thanks to Tom_E. Thank you so much for this great UI. Your hard work on this code is very much appreciated.
NarsilMQ8 at moonlight setting 2.
I just wanted to add this here, if when you switch from the attiny13a programming to the attiny85 and you have any kind of problems trying to get the programmer to talk to the attiny85, go back and check to make sure all your connections are correctly wired like here. I have had my USBasp wired up according to Wiki for years, way back when Tido started this whole craze. Never gave any problems with the attiny13a but refused to work with the attiny85. Pulled all my wires out of the clip and USBasp and wired it up accordingly to hoop's guide, and bam, worked the very first time. I spent hours trying to figure out what was wrong. Maybe this will save someone the trouble. I found out from a post by Tom_E describing the same problem when he switched to the 85. Thanks again Tom_E.
