Moodz' Awesome Gold Pulse Induction Version 3 - MAGPI V3 Project

[Dean Sarelius]

Hi All,
Everything appears to be working ok.
The issue with the display was the contrast control on the back of the SPI display controller.
Running the display with 3.3V I had to set the contrast control pot to its limit and it is still not very good.
Lucky I provided a 5V backlight option and the contrast is much better.
In order to use the SPI display controller in 5V mode you need to remove two pull up resistors on the SPI controller pictured below labelled R8 and R9.
You also need to add 2 x 4.7k pull up resistors on the main board.
There is a spare header on the main board for the 5V option.
Before I can test with a coil am expecting to receive the surface mount IRFP9640S next week .
in the meantime I will be adding the encoder and testing the audio circuitry over the weekend.
When all this is done and dusted will start a new thread where I will post all the files.

[IBGold]

Hi the firmware is below ...

https://www.geotech1.com/forums/foru...964#post412964

Hi Paul finally got V1.4 programmed first came up with no voltage to VDD then wrong target ID but after 12 goes it finally programmed any way after playing for a while I have some suggestions can you separate threshold volume from target volume because as it is now if you set the volume to a steady low threshold volume the volume of small targets in fact all targets at the lower limits of detection are not loud enough to hear also could you give us a list of what the Menu items are and what they do Volume, Tone, Battery and balance are probably self explanatory it is the other items and their inter relations with that knowledge I would be happier playing around with the settings sorry to be a pain.

Regards, Ian.

[moodz]

Hi Paul finally got V1.4 programmed first came up with no voltage to VDD then wrong target ID but after 12 goes it finally programmed any way after playing for a while I have some suggestions can you separate threshold volume from target volume because as it is now if you set the volume to a steady low threshold volume the volume of small targets in fact all targets at the lower limits of detection are not loud enough to hear also could you give us a list of what the Menu items are and what they do Volume, Tone, Battery and balance are probably self explanatory it is the other items and their inter relations with that knowledge I would be happier playing around with the settings sorry to be a pain.

Regards, Ian.

errmmm ... the last version 1.4 I left some test timings in there ... I will need to re-release it ... It wont break the detector but the TX is wrong.

[moodz]

Hi All,
Everything appears to be working ok.
The issue with the display was the contrast control on the back of the SPI display controller.
Running the display with 3.3V I had to set the contrast control pot to its limit and it is still not very good.
Lucky I provided a 5V backlight option and the contrast is much better.
In order to use the SPI display controller in 5V mode you need to remove two pull up resistors on the SPI controller pictured below labelled R8 and R9.
You also need to add 2 x 4.7k pull up resistors on the main board.
There is a spare header on the main board for the 5V option.
Before I can test with a coil am expecting to receive the surface mount IRFP9640S next week .
in the meantime I will be adding the encoder and testing the audio circuitry over the weekend.
When all this is done and dusted will start a new thread where I will post all the files.

good job

[Dean Sarelius]

Hi Dean ... yes I had a look at the rotary wiring and you are right I have wired the C ( common ) to the B switch Good Pickup !
So I changed the wiring to AB and C to common and its still works OK ... so I guess the code and the wiring is foolproof by accident.

I have never used interrupts for rotary encoders ...if you have some other more critical loop task ( like the TX interrupts ) then if the loop is fast enough to sample you get a rotary encoder or multiple REs with very little code overhead plus free debounce.

The less interrupts the better I always say.

moodz.

Hi Moodz,
Just in the process of re-configuring the V1.4 firmware which I have renamed to V3.11.
Could you remind me which pins you ended up using for the Encoder..?

[IBGold]

Could we not just connect VCC on the LCD serial board to VP (5V) instead of VL I will try and find a VP access point and try it as with the 3.3V I also have contrast difficulties.

Regards, Ian.

[Dean Sarelius]

Hi Moodz,
Just in the process of re-configuring the V1.4 firmware which I have renamed to V3.11.
Could you remind me which pins you ended up using for the Encoder..?

Hi Moodz,
No need to reply I found the declerations for the endoder...cheers

[moodz]

[Dean Sarelius]

Hi Moodz,
Completed the mods to the code and everything appears to be working just waiting for the fet to arrive before completing the testing.
What I would like to know is if the valriables like VOL, TON, S2S etc are supposed to be saved before power cycling the detector...?
At the moment it appears that the variables always revert back to their reset values like VOL: 010 and TON: 000.

[IBGold]

Hi Moodz,
Completed the mods to the code and everything appears to be working just waiting for the fet to arrive before completing the testing.
What I would like to know is if the valriables like VOL, TON, S2S etc are supposed to be saved before power cycling the detector...?
At the moment it appears that the variables always revert back to their reset values like VOL: 010 and TON: 000.

The current user set settings are not saved on turn off it reverts to default.

Regards, Ian.

[moodz]

The current user set settings are not saved on turn off it reverts to default.

Regards, Ian.

err ... theres a method in the code to do it but still on to do list

[IBGold]

Hi I have been playing again and connecting VCC on the LCD to VP (4.98V) in my case works a treat full control of LCD contrast and so far no downsides.

Regards, Ian.

[IBGold]

err ... theres a method in the code to do it but still on to do list

Hi Paul how's the to do list and the code update going.

Regards, Ian.

[JoyJo]

Let me ask you something. In the original scheme, the TX cascade is powered by 5V.

Does it make sense to consider increasing the power of the pulse and the detection depth by increasing the power supply to 9V. Why up to 9V? I have experience using a tank-boost converter with just such an output voltage. increasing the supply voltage to 9V should also increase the pulse power? Will it be useful? There is also a small clarification on the D3 diode. It can be replaced with an SMD variant, for example ES3D-E3/57T (200V, 3A, 30ns, 45pF).

[moodz]

Let me ask you something. In the original scheme, the TX cascade is powered by 5V.

Does it make sense to consider increasing the power of the pulse and the detection depth by increasing the power supply to 9V. Why up to 9V? I have experience using a tank-boost converter with just such an output voltage. increasing the supply voltage to 9V should also increase the pulse power? Will it be useful? There is also a small clarification on the D3 diode. It can be replaced with an SMD variant, for example ES3D-E3/57T (200V, 3A, 30ns, 45pF).

The supply could be changed to 9 volts but in the original design the limiting factor was the P type mosfet which has a relatively low avalanche voltage. As you increase the power ( current ) in the coil the flyback voltage at TX off may cause avalanching of the TX mosfet and this will degrade the performance.

Also make sure that Q2 is not driven to avalanche or the damping loop will stop working. ( ie flyback voltage must be less than avalanche point of Q2 )

Feel free to experiment though.

D3 can be changed to SMD no problem.