Search found 167 matches

by dannyf
Sun Dec 10, 2017 2:34 pm
Forum: General discussion
Topic: Programmer's Manual?
Replies: 7
Views: 189

Re: Programmer's Manual?

The Definitive Guide to ARM® Cortex®-M3 and Cortex®-M4 Processors6 Oct 2013 | Kindle eBook by Joseph Yiu Yiu's book has limited value from a practitioner's perspective, as the core is for the most part transparent to the programmer. the peripherals, as described in the datasheet, are what we deal w...
by dannyf
Sat Dec 09, 2017 6:58 pm
Forum: Off topic
Topic: STM32 powered multimeter
Replies: 14
Views: 816

Re: STM32 powered multimeter

actually stm32f103 with 12 bits adc, my guess is that it is literally pretty accurate as 2^12 = 4096
for a noise free measurement, a 12bit adc may deliver 10bit, and likely 9.x bits. Plus, the inability to use dual reference in makes it harder.
by dannyf
Sat Dec 09, 2017 6:55 pm
Forum: Ideas & suggestions
Topic: How to evaluate digitalWrite at compile time?
Replies: 8
Views: 734

Re: How to evaluate digitalWrite at compile time?

If the parameters are constant, I want digitalWrite(pin, val) to evaluate it at compile time. Down to one instruction. for what end? presumably for efficiency. but that's not high on arduino's priority list: this thing is geared to people who want to write generic code with minimum efforts. if you ...
by dannyf
Sat Dec 09, 2017 2:44 pm
Forum: Off topic
Topic: STM32 powered multimeter
Replies: 14
Views: 816

Re: STM32 powered multimeter

the simplest way to get +/- 32000 counts is with ADS1100
I'm a big fan, for adc, of F350 from Silabs. 24bit adc, and PGA. the only catch there is your choice of oscillator to minimize jitter.
by dannyf
Fri Dec 08, 2017 7:48 pm
Forum: General discussion
Topic: Programmer's Manual?
Replies: 7
Views: 189

Re: Programmer's Manual?

as opposed to the 1000 page STM32 processor manual
that manual / datasheet is the best friend to any embedded programmer. if you aren't willing or able to read it, embedded programming will be a tough job for you.

there really is no other way around it.
by dannyf
Fri Dec 08, 2017 1:06 pm
Forum: General discussion
Topic: [SOLVED] EEPROM i2c - use negative values
Replies: 5
Views: 99

Re: EEPROM i2c

I would like to record negative values.
negative values are the same as positive (unsigned) values. the code is written to be able to handle both.
by dannyf
Sat Dec 02, 2017 1:22 pm
Forum: General discussion
Topic: INPUT_PULLDOWN
Replies: 23
Views: 462

Re: INPUT_PULLDOWN

but almost work almost surely, except when it doesn't. a similar trap exists on older the older luminary chips: if your code executes so fast that it disables the debug pins before the connection is made, you will never be able to debug the chip. A recent example is here: https://dannyelectronics.w...
by dannyf
Fri Dec 01, 2017 1:54 pm
Forum: General discussion
Topic: INPUT_PULLDOWN
Replies: 23
Views: 462

Re: INPUT_PULLDOWN

Maybe there is no difference in analog performance between the two modes, but we save some power by using INPUT_ANALOG instead of INPUT?
yeah. the datasheet is quite clear on that: the only difference is the de-activation of the input buffer under the analog mode.
by dannyf
Fri Dec 01, 2017 2:18 am
Forum: General discussion
Topic: Password storage on a BluePill
Replies: 35
Views: 501

Re: Password storage on a BluePill

a few things: 1) UID would be great: the password being stored / exchanged with the host / authenticator can be encrypted with the UID before it is stored on the chip. a lowly STM32 or STM8 can do that and be used to store practically limitless amount of passwords; 2) the key here will be figuring o...
by dannyf
Wed Nov 29, 2017 6:33 pm
Forum: STM Nucleo boards
Topic: [SOLVED]How to read the ID number?. REG [UID]
Replies: 3
Views: 256

Re: [SOLVED]How to read the ID number?. REG [UID]

Very simple.

1. Read the datasheet - this is always going to be your first step.

2. Find out where the uid is located, as their location is family specific.

3. Fix a data type of your choice to that address.

4. Done.