Search found 634 matches

by ag123
Mon Jun 26, 2017 1:28 pm
Forum: General discussion
Topic: does stm32f1 gets too hot in a project box? and temperature sensor
Replies: 6
Views: 111

Re: does stm32f1 gets too hot in a project box? and temperature sensor

ok thanks ! that sounds encouraging, would shop around for a box and try to fit them in :D stm32f103 maple mini / blue pill + ili9341 maybe + some buttons (mine didn't have the touch screen, but get the touch screen one if you are getting an lcd) as it seemed is a pretty good bundle of things to put...
by ag123
Mon Jun 26, 2017 12:52 pm
Forum: General discussion
Topic: does stm32f1 gets too hot in a project box? and temperature sensor
Replies: 6
Views: 111

Re: does stm32f1 gets too hot in a project box? and temperature sensor

thanks pito, fred, i'm thinking of fitting a maple mini + ili9341 display in a plastic 'project box' https://www.ebay.com/sch/i.html?_from=R40&_nkw=project+box&_sacat=0 at the moment trying to figure out how to make the holes (e.g. for the lcd) and how to fasten the components, maple mini do not hav...
by ag123
Sun Jun 25, 2017 3:21 pm
Forum: General discussion
Topic: does stm32f1 gets too hot in a project box? and temperature sensor
Replies: 6
Views: 111

does stm32f1 gets too hot in a project box? and temperature sensor

has anyone placed an stm32f1 (blue pill / maple mini) in an enclosed project box? does it 'get too hot' in an enclosed project box? apparently there is an internal temperature sensor on the stm32 (f103) but is apparently 'seldom used' http://www.programering.com/a/MDN3IDNwATE.html http://www.onarm.c...
by ag123
Sun Jun 25, 2017 2:57 pm
Forum: General discussion
Topic: Should we still use optimisation level -Os (Small)
Replies: 15
Views: 193

Re: Should we still use optimisation level -Os (Small)

*single precision* floating point on f4 is *very fast* in part due to hardware fpu x2 (there is 2 fpu in there) + ART memory accelerator http://www.stm32duino.com/viewtopic.php?f=39&t=2001 hence if there is a a lot of *single precision* floating point calcs f4 may be the 'right platform' to run it i...
by ag123
Sun Jun 25, 2017 8:43 am
Forum: General discussion
Topic: Should we still use optimisation level -Os (Small)
Replies: 15
Views: 193

Re: Should we still use optimisation level -Os (Small)

i'd live with -Os (small) optimizations on maple mini/ blue pill, the -O2 optimizations seem to help in particular on the F4 nevertheless -Os (small) is still preferred for F4 as a default mode i think the main reasons -O2 is faster on F4 are due to 'indiscriminate' optimizations by gcc/g++ (the com...
by ag123
Sun Jun 25, 2017 8:22 am
Forum: General discussion
Topic: SD card on ILI9341 display board??
Replies: 17
Views: 219

Re: SD card on ILI9341 display board??

it do sound like there are various 'versions' of ILI9341 boards floating around, my guess is that the components between different batches of boards are different or even within the same batch it may be different. hence, to be safe, it'd probably be better to be somewhat careful, have a multi-meter ...
by ag123
Sun Jun 25, 2017 8:13 am
Forum: General discussion
Topic: SD card on ILI9341 display board??
Replies: 17
Views: 219

Re: SD card on ILI9341 display board??

on my board for the backlight led pin i initially connected a 220 ohm resistor measure voltages and worked out the on board series resistance. it turns out that the on-board series resistance is 900 ohm in my case http://www.stm32duino.com/viewtopic.php?f=45&t=526&p=27193#p27193 my guess is that if ...
by ag123
Sun Jun 25, 2017 7:58 am
Forum: General discussion
Topic: Combining Blink & Count to the bootloader
Replies: 33
Views: 376

Re: Combining Blink & Count to the bootloader

thus far i'm quite happy with just the 'raw' bootloader, in fact after i installed the bootloader i deliberately zero out blocks of flash after 0x8002000 if i remember correctly, this leaves it in 'perpetual' boot loader mode waiting for sketch install either way the 'perpetual mode' keeps the led b...
by ag123
Sat Jun 24, 2017 7:02 am
Forum: General discussion
Topic: SD card on ILI9341 display board??
Replies: 17
Views: 219

Re: SD card on ILI9341 display board??

for the backlight, i feed a normal gpio pin directly from my maple mini to the backlight pin. http://www.stm32duino.com/viewtopic.php?f=45&t=526&p=27193#p27193 But before you do that, try first with a resistor say a few hundred ohms connecting in series to the backlight pin and measure voltages. i t...
by ag123
Sat Jun 24, 2017 6:10 am
Forum: General discussion
Topic: SD card on ILI9341 display board??
Replies: 17
Views: 219

Re: SD card on ILI9341 display board??

i shorted those series resistors on mine, simply replace them with a single strand of wire each http://www.stm32duino.com/viewtopic.php?f=44&t=2026#p27139 i removed the resistors this way and later solder wires in its place https://www.youtube.com/watch?v=8JM4oCpWnjU it works well for me however, as...