Search found 1630 matches

by ahull
Thu Nov 23, 2017 1:06 am
Forum: Projects
Topic: Complete dashboard for an old car
Replies: 12
Views: 195

Re: Complete dashboard for an old car

Here is a similar (arguably better) idea using two mosfets. http://www.mosaic-industries.com/embedded-systems/microcontroller-projects/electronic-circuits/push-button-switch-turn-on/microcontroller-latching-on-off The description of how it works should give you a few ideas. My idea is a little simpl...
by ahull
Wed Nov 22, 2017 9:01 pm
Forum: Projects
Topic: Complete dashboard for an old car
Replies: 12
Views: 195

Re: Complete dashboard for an old car

You could use a relay and a couple of optoisolators in parallel. The ignition switches on one optoisolator, this provides power to the relay coil, the relay then provides power to the 5V PSU/regulator for the STM, which in turn on power up, switches on optoisolator 2 which is parallel with optoisola...
by ahull
Wed Nov 22, 2017 2:43 am
Forum: Projects
Topic: Complete dashboard for an old car
Replies: 12
Views: 195

Re: Complete dashboard for an old car

I suspect you will need a capacitor of a few hundred uF to run the STM for sufficient time after the 12V goes down. You will also need some form of brownout detection on the 12V line (you may get away with polling a simple voltage divider from an analog input) so you know the power has gone. The siz...
by ahull
Fri Nov 17, 2017 2:01 am
Forum: Off topic
Topic: "New" "Multimeter"
Replies: 12
Views: 447

Re: "New" "Multimeter"

Very nice.. Complete with original user manual I see. :D
by ahull
Thu Nov 16, 2017 7:33 pm
Forum: Code snipplets
Topic: EEPROM emulator for 8-bit data
Replies: 8
Views: 155

Re: EEPROM emulator for 8-bit data

If you only have a few values to store, you could always use the RTC NVRAM bytes (but you would have to add a battery). I believe the RTCs 10 x 16 bit "backup registers" have a near infinite number of write cycles, and can also be written bytewise as opposed to sector wise. // Define the Base addres...
by ahull
Thu Nov 16, 2017 9:30 am
Forum: Off topic
Topic: MicroPython News
Replies: 20
Views: 2101

Re: MicroPython News

But todays fun thing is to buy a kids kite Even more fun is to make your own kites. When I was much younger I used to build big kites out of heavy duty polythene (thick bin bags or plastic animal feed bags). The lift these things generated was sometimes a little scary (especially since I lived unde...
by ahull
Tue Nov 14, 2017 9:44 pm
Forum: Off topic
Topic: Uncle Andrew.. how come we have a $2 multi MHz board?...
Replies: 23
Views: 380

Re: Uncle Andrew.. how come we have a $2 multi MHz board?...

If the chipset supports USB host mode (and this is also supported by the Custom ROM), you can add USB serial peripherals, SPI bridging and some gpio (by bitbanging the handshaking pins) . Other hardware (keyboards, mice, HID devices etc) are also available using host mode. Having said that, you can ...
by ahull
Tue Nov 14, 2017 6:48 pm
Forum: Off topic
Topic: Uncle Andrew.. how come we have a $2 multi MHz board?...
Replies: 23
Views: 380

Re: Uncle Andrew.. how come we have a $2 multi MHz board?...

ag123 wrote:
Tue Nov 14, 2017 5:25 pm
i've been wanting to install a custom rom on my phone so that those pesky apps won't complain that the phone is rooted. A truly custom rom probably doesn't need root, as everything can be root if u want it to be :lol:
What make/model of phone?
by ahull
Tue Nov 14, 2017 4:22 pm
Forum: Off topic
Topic: Uncle Andrew.. how come we have a $2 multi MHz board?...
Replies: 23
Views: 380

Re: Uncle Andrew.. how come we have a $2 multi MHz board?...

If the Android phone can be rooted (this is becoming more difficult) Older Samsung devices are perfect for re-purposing, and a lot of them are relatively easy to root. If you are up for a little bit of surgery, you can pick them up with a broken screen for pocket money prices. The replacement scree...
by ahull
Tue Nov 14, 2017 2:04 pm
Forum: Off topic
Topic: Uncle Andrew.. how come we have a $2 multi MHz board?...
Replies: 23
Views: 380

Re: Uncle Andrew.. how come we have a $2 multi MHz board?...

.. and of course old (ARM based) Android phones can be used as crude oscilloscopes, and fancy calculators.. and controllers for ESP wifi enabled gadgets, and as signal generators, and musical instrument tuners, and metronomes... and... GPS loggers .. and remote voice bugs...