Jazzing up the Arduino PI - full recipe

[SaltyDog]

Gunghouk I implemented MOD2 but found it modulated too much, overloading on large targets. So I found I could remove all the MOD2 components, and instead,just wire A1 to the base of Q5, that works much better, still get adequate modulation, but no overloads.
Signal will be roughly max 1.5v at that point.

I could also play with this line, to get more modulation if I wanted, with the above signal.

freq = map(target, 0, 635, FREQ_MIN, FREQ_MAX);

[SaltyDog]

Teleno I have bumped up the main clock to 32mHz. However, the audio tone frequency appears to be doubled. This is maybe due to the line:

#define TIMER2_CLK (F_CPU >> 8)

The Timer2 clk has doubled. Or has my ears deceived me ..

EDIT: Never mind, just measured it at 982Hz ..

[Teleno]

Teleno I have bumped up the main clock to 32mHz. However, the audio tone frequency appears to be doubled. This is maybe due to the line:

#define TIMER2_CLK (F_CPU >> 8)

The Timer2 clk has doubled. Or has my ears deceived me ..

EDIT: Never mind, just measured it at 982Hz ..

For this project there's no advantage in doubling the system clock. On the contrary, the internal 32MHz are RC generated and jittery, use the 16MHz crystal clock instead.

[SaltyDog]

For this project there's no advantage in doubling the system clock. On the contrary, the internal 32MHz are RC generated and jittery, use the 16MHz crystal clock instead.

Yes, I do use the 16Mhz XTAL, just trying the 32Mhz to check code action The only downside I see (apart from jitter) is that the audio chopper freq has doubled.
(It was 490Hz in the original project)

[SaltyDog]

I am about to pot my "fast" coil, any suggestions on a pourable epoxy that has low dielectric constant? Cheers.
Epoxyseal 9000 Looks good, but can't find a supplier that ships to NZ

[Teleno]

I am about to pot my "fast" coil, any suggestions on a pourable epoxy that has low dielectric constant? Cheers.
Epoxyseal 9000 Looks good, but can't find a supplier that ships to NZ

https://www.google.com/search?q=pott...ics+site%3A.nz

[SaltyDog]

https://www.google.com/search?q=pott...ics+site%3A.nz

Very funny Ha Ha .... Don't you think I did that? It is very hard getting specs to make sure the epoxy does not degrade the fast coil.

[Carl-NC]

Epoxyseal 9000 Looks good, but can't find a supplier that ships to NZ

I just received some Epoxyseal 9000, got it from Amazon but I see it's not on Amazon.au. Never tried it before. I suppose you looked through AliExpress?

[SaltyDog]

I just received some Epoxyseal 9000, got it from Amazon but I see it's not on Amazon.au. Never tried it before. I suppose you looked through AliExpress?

Yep, none at Ali, will keep looking.

[SaltyDog]

I did find some: https://www.synergyelectronics.co.nz...cy-epoxy-resin
Has some good specs and Dielectric constant of 4 (permittivity)

Here is my coil ready to be epoxied .. shield is made up from a mixture of Elmer's Glue and powdered graphite .. works well.
I will embed in a coil support, soon as I have it printed ..

[Teleno]

Very funny Ha Ha .... Don't you think I did that?

You got a short fuse, man. But...

...Synergyelectronics.co.nz ranks second in the results of the search link I gave you, and the product you selected is from Electrolube which ranks first.

So if you had really dunnit as you pretend then you would have found it before.

No thanks, man, and feel free to derail my thread too, of course.

[SaltyDog]

This thread is "jazzing-up-the-arduino-pi" right? Thought having a fast coil to go with the electronics would be appreciated, but your thread, your call........I'm out ..

[KenS]

Is there a discrepancy between the implementation of PCB mod1 and the final schematic (wrt ArduinoPI_fullPWM_1_0_5) ?
The PCB mods move R11 to connect to a new Arduino pin8(D5) which is OK.
The PCB mods move R5 to connect to freed-up Arduino pin13(D10) which is OK, but the remains of that net i.e. U2 Oscillator (pin7) is left still connected to Arduino pin11(D8 ) which is shown as a no connect in the marked-up schematic. Doesn't this leave the oscillator unsync'ed? Doesn't R1 north need lifting and connecting to Arduino pin13(D10) also?
Am I missing something?

[KenS]

I have completed my build, all running well. I made slight change to the mods for swapping Arduino pins 8 &13, also added a pair of resistors to provide a Battery monitor at Arduino pin21 (A2) and tweeked the Arduino sketch to add the battery monitor. Just got some PTFE wire to see if there is any noticable difference when used for the search coil in place of PVC wire. (hope adding attachements works OK)




Schematic_mods bat.pdf
ArduinoPI__1_0_5_with_battery_monitor.zip

[Carl-NC]

Nice work! I assume you figured out the R1 issue.