Electronics chit-chat

[esaj]

15 minutes ago, euc said:

For 3.3V projects I really recommend the ESP8266. They have much better specs than Arduinos, they are half the size, they have Wifi built it and they only cost like 2 bucks a piece.

Thanks, I'll take a look at them... although I really should refrain from ordering more stuff all the time (500+ orders from Aliexpress within the last year, and almost all of it is electronics components and modules... )

 

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They can also be programmed with the Arduino IDE and you can also flash a custom firmware which allows you to write your whole code in Lua which makes coding like 10 times easier. It's even possible to upload your code OTA, which is ridiculously awesome.  

I like the idea of OTA-upload, but for me, Lua actually would make coding 100x harder, as I've spent decades working on imperative, statically typed (or is it strongly typed? I always mix those) languages, and prefer them to anything with dynamic typing or functional paradigms  

 

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Downside is that they only operate at 3.3V. (Although if you get a logic level converter nothing would stop you from using it in a 5V project)

I've got a bunch of 3.3V switching regulators, or I build my own from a power Mosfet & opamp, if need be    Probably also got those logic level converters... somewhere in the bins 

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Atm I'm waiting for the ESP32 (which comes out in 10 days). It's basically like an ESP8266, but the specs are much higher and it also has Bluetooth built in. That thing will hopefully replace the bulky combination of a pro mini and an HC-05.

I've been eyeing at getting a Raspberry (or Banana or Orange or whatever) Pi at some point, but A) I really don't have any project that would need a really fast MCU that's more like a computer, and B )  I already get to code as much as (and more than) I want at work, so lately I've preferred to learning and working with analog electronics

 

14 minutes ago, Keith said:

Ah thank you @esajand @euc, the lack of an odometer and IOS app for my older KingSong have always been a bit of a pain and I can't be bothered to carry an Android phone with me as well. You have, between you now got the cogs whirring in what passes for my brain........ Now can I tap the USB power supply in my KS-14, fit the electronics inside (no problem at all I've got an empty battery bay) and have both speed (or possibly Watt hours consumed) and total mileage displayed actually on the wheel, relying on the Arduino to keep the odometer running total. It has got to be worth trying hasn't it?

Btw, I wrote wrong in the above post (" there's an extra 0x00 -byte in front of the header "), actually there's 0x04 in the Gotway-version at that point, so there's 0x00 instead of 0x04... anyway, if you only check for the " 18 5A 5A 5A 5A 55 AA " -header and start reading after that, you get the values in KS, but not odometer, just trip, ie. it zeroes when the wheel is turned off. But you can of course save it in EEPROM in the MCU (just don't write it all the time, but maybe after every 100 meters or so, the EEPROMs have limited rewrite amounts before they become unusable/don't hold data reliably anymore).

 

 

[euc]

4 minutes ago, esaj said:

Raspberry (or Banana or Orange or whatever) Pi at some point, but A) I really don't have any project that would need a really fast MCU that's more like a computer

Same here. But the price is just way too high and the clones are not really compatible with existing Raspi codes. (At least that's what I've been told.) 

10 minutes ago, esaj said:

Thanks, I'll take a look at them... although I really should refrain from ordering more stuff all the time (500+ orders from Aliexpress within the last year, and almost all of it is electronics components and modules... )

Looks like we have a lot in common.  
Btw there are several different versions of the ESP8266. ESP-07, ESP-12 and ESP-14 are the most interesting ones imo.

[esaj]

3 minutes ago, euc said:

Same here. But the price is just way too high and the clones are not really compatible with existing Raspi codes. (At least that's what I've been told.) 

Yeah, that's another good point, I really can't justify spending something like 50€ (well, less for the clones) on a board that I might not even use ever for anything

 

3 minutes ago, euc said:

Looks like we have a lot in common.

I got "back" to electronics only recently (well, actually since last November or so), but I did have some education in electricity / electronics over a decade ago. Still, I'd say I've learned more within these last 9-10 months or so than back then at school in a few years   I've kept my electronics escapades ramblings in the off-topic section here, as they're not really EUC-related:

 

 

[esaj]

8 minutes ago, euc said:

I soldered the parts together and added a switch between the lipo and the boost converter. I also used wires instead of PCB to reduce thickness.
But I'm not too happy with the results:  It looks like a mess... It's 17mm in thickness btw.

Nice, you could even fit the battery there.

I'd say that's not a mess, this is a mess (an ATX-PSU control box & outputs):

As long as it works, doesn't cause short circuits and you can enclose it, who cares if it's messy inside?

 

Can't tell anything of the mess from the outside and everything works, so... success?

 

8 minutes ago, euc said:

When I have some more time I will probably 3d print a nice enclosure for the thing and add straps to it, so that I can actually wear it without making everyone think I'm a terrorist.

3D-printer would be nice, but I've been eyeing at a PCB-milling machine (small CNC) instead. I know you can order factory-made PCBs very cheaply (like $10-$20 per 10 boards), but the roundtrip from designing the board to getting them can easily be a few weeks, so prototyping at home would seem more useful to me (and then once you're happy with the design, order factory-made PCBs). A friend of mine just ordered 10 boards and did a small design fault, so after waiting a few weeks, he still ended up having to add jumpers and such  Something that could have been avoided had he been able to mill the prototypes first, and only after that order the PCBs  Price-wise, you can probably order something like 500 boards with the price of the mill, and even more if you count how many bits need to be replaced to make same amount of boards etc, so not really that economical in comparison...

[euc]

Wow, I'm really glad a have a lab psu. Although I have to say that having more than one set of banana connectors would be really nice. 

And yes, PCB-milling machines are awesome. I actually know some guys who would let me user their machine, but I'd have to learn how to use the software because they are pretty busy working on bigger projects like this one:

 

[Battling]

Great job, I was hoping to use @esaj's code published here

But, thanks to your library, we can directly access to the beast's thoughts so thank you.
For space saving, I use a standalone atmega328 in my MCM4 and it works great with the HC-05. As you need only 4 I/O for your smartwatch, you even could use an Attiny85 with internal oscillator and SoftwareSerial for example.

You also could unsolder the HC-05 from his "shield" and use only the module's heart (as you have a 3.7V battery, no need of the regulator, switch, LED, ...)

[esaj]

14 minutes ago, Battling said:

Great job, I was hoping to use @esaj's code published here

But, thanks to your library, we can directly access to the beast's thoughts so thank you.
For space saving, I use a standalone atmega328 in my MCM4 and it works great with the HC-05. As you need only 4 I/O for your smartwatch, you even could use an Attiny85 with internal oscillator and SoftwareSerial for example.

You also could unsolder the HC-05 from his "shield" and use only the module's heart (as you have a 3.7V battery, no need of the regulator, switch, LED, ...)

Now what board is that? Actually, don't tell me... I already "had" to order ESP8266-based boards today (and might have slipped a little more this and that in the same order, like Nema17-steppers...).  @euc I blame you   I already have drawers full of Unos, Nanos, Pro Minis, Megas, Lilypads, AtTiny-chips & programmers and boards...

[Battling]

That's the HC-05 unsoldered, I think you already have one and no need to order it Stop ordering, your postman will go mad

 

 

 

 

[esaj]

29 minutes ago, Battling said:

That's the HC-05 unsoldered, I think you already have one and no need to order it

Right, had to check, mine have those golden "checkmarks" like in euc's picture  And they're the unsoldered kind (ie. separate baseboards). Also found a large bunch of 2.4GHz wireless boards and something like 900MHz 400MHz radio transmitters/receivers in the same bin, already forgot I had those 

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Stop ordering, your postman will go mad

I've actually wondered when the day will come, that the doorbell will ring and I have to face a very pissed off postman...   I can't have more than... 40-ish orders on the way currently   And a big bunch of half-finished projects... Actually, just finished a BMS(ish) thingamabob for 2S-Li-Ion pack (can't really call it a BMS, as it only has overvoltage protection for charging, undervoltage protection for discharging and PTC's to handle short circuits / overcurrents, no balancing)   Just getting ready to test it with the real cells. If you don't hear from me in a couple of days, send flowers to the funeral.

[Battling]

That's not a workshop you have but an Aladdin's cave!

I also have some of the 433/315MHz T/R and others nRF24L01. I used the firsts in outlets, roller shutters and lamp bulb sockets (the all with Attiny85). But just tried the nRF which I bought for a "mysensors" system than I never built.
 

31 minutes ago, esaj said:

I've actually wondered when the day will come, that the doorbell will ring and I have to face a very pissed off postman...

No worry, he blesses you because he knows that as you receive small packets, he keeps his job.
 

38 minutes ago, esaj said:

Actually, just finished a BMS(ish) thingamabob for 2S-Li-Ion pack (can't really call it a BMS, as it only has overvoltage protection for charging, undervoltage protection for discharging and PTC's to handle short circuits / overcurrents, no balancing)

Perhaps we'll have our first DIY BMS tutorial!
 

39 minutes ago, esaj said:

 Just getting ready to test it with the real cells. If you don't hear from me in a couple of days, send flowers to the funeral.

A solution is the use of your T/R to activate the BMS remotely for the first tests, so no risks for you

[esaj]

56 minutes ago, Battling said:

That's not a workshop you have but an Aladdin's cave!

It's a small-scale junkyard (at least at times), that's what it is

56 minutes ago, Battling said:

Perhaps we'll have our first DIY BMS tutorial!

A solution is the use of your T/R to activate the BMS remotely for the first tests, so no risks for you

I did test it with the real cells, and am still alive

 

 

[lizardmech]

That ESP32 MCU looks interesting. I have been playing around with cypress PSoC5LP, I was able to turn a $10 board with one into a makeshift oscilloscope without any external components, it has strange programmable logic on chip that be turned into opamps and other hardware. I wish I could use it in a EUC controller but it only has a ARM m3 MCU @ 80mhz with no FPU so something like the VESC firmware can't be ported. I need to find someone who can reverse engineer the motor observer code portion in the VESC so I can use it on other MCUs. That one small section of code is pretty much the key to making open source high performance FOC motor controllers but the guy who wrote has been missing for 2 months.