24mhz, no OLED attached, totally absent from code too, 5v source, no usb: Waiting for keypress: 27ma Writing to serial port at 115200: 32ma Writing to sdcard: 50ma
This is more like what a tpdd emulator would be. Or less because I think even the 2mhz is enough for tpdd. This includes the rs232 level shifter as before. On Sun, Aug 26, 2018 at 9:48 AM Brian White <[email protected]> wrote: > Ok, got some numbers. > Conditions: > > Main board: Teensy 3.6 > Adata 8G class 4 sd card inserted. (different cards draw more or less) > 128x64 mono OLED attached by I2C and lit up with a screen of text. > https://www.velleman.eu/products/view/?id=439232 > Serial1 connected to a level-shifter to a pc > http://schmartboard.com/schmartboard-rs-232-module-710-0001-01/ > > http://www.analog.com/media/en/technical-documentation/data-sheets/ADM2023_1181A.pdf > The level-shifter is powered from one of the 3.3v pins provided by the > Teensy, ie, NOT from the Vin or VUSB that feeds the Teensy itself. (this is > mostly just to protect the Teensy io pins from getting more than 3.3v from > the level-shifter, but it also means the current draw number > includes the level-shifter) > RTS and CTS lines actually connected to level-shifter too. > > USB not connected. Power coming from a plain 5v supply to the Vin pin on > the Teensy, with ammeter in series. > > on-board led lighted during sdcard access > > Voltage measured at the Teensy and while under load > > Running at 2mhz: > While waiting for a keypress: 18.3ma @ 5.07v > While writing to sdcard: 33-38ma @ 5.07v > > Running at 24mhz: > While waiting for a keypress: 36ma > While writing to sdcard: 59-66ma > > Running at 180mhz (default): > While waiting for a keypress: 96ma @ 4.98v > While writing to sdcard: 96-130ma @ 4.7v > > This is with no special tricks to go idle and draw low power. I think > there are lowpower libraries that can do some things, and definitely there > are purely eltronics ways to cut power and restore power based on serial > activity. But my test code right now is just sitting in a loop reading the > serial port. > > > On Fri, Aug 24, 2018 at 6:36 PM Brian White <[email protected]> wrote: > >> Well that's a downside of working in an unorthodox location, I don't have >> any way to measure current right now :) >> https://photos.app.goo.gl/rq2TM5cWNV8NMkyi8 >> >> >> On Fri, Aug 24, 2018 at 3:15 PM Fugu ME100 <[email protected]> wrote: >> >>> That sounds great. What sort of current draw are you getting? Quite >>> curious. >>> >>> ------------------------------ >>> *From:* M100 <[email protected]> on behalf of Brian >>> White <[email protected]> >>> *Sent:* Friday, August 24, 2018 20:12 >>> *To:* [email protected] >>> *Subject:* Re: [M100] New Age Digital Storage Box (NADSBox) >>> >>> I was playing with the Teensy 3.6 some more last night and got it >>> waiting & responding to commands by serial (the built-in ftdi usb-serial >>> not via max232 yet), reading/writing to files in a fat32 fs on the sd, >>> blinking the on-board led during drive activity, and displaying text on a >>> tiny 128x64 0.96 inch oled display via i2c. >>> >>> All while sitting at a counter at a diner. >>> >>> Because it didn't need anything but a laptop, usb cable, and the chip >>> stuck on the end of the cable, and 4 jumper wires just for the oled display >>> which was just for play anyway, probably wouldn't actually want that on the >>> finished device. >>> >>> These arduino libraries and built in examples make it all pretty easy to >>> get started. >>> >>> And teensy has an rtc built-in too. Needs another battery, but a cr2032 >>> can apparantly keep the rtc going for about 17 years, so, not a problem. >>> >>> This 32 bit 180mhz cpu is overkill, but it's just handy having the sd >>> card reader and usb port already built in. The cpu can be underclocked in >>> software but I don't know if it goes all the way down to 4! >>> >> >> >> -- >> bkw >> > > > -- > bkw > -- bkw
