PPM MarkIV project progress report

[Willy Bayot]

It would indeed be interesting to make some experiments with Bluetooth-based GPS.
For that, we would need a Bluetooth base station to be connected to our PPM.

Willy

I have found a number of Bluetooth modems at www.SparkFun.com and I bought one to experiment with it.

Willy

[Willy Bayot]

Willy I have been following your project for a while now and think its one of the most outstanding projects in the treasure hunting scene.

How do you link in GPS? Do you have any plans to use mobile phones for GPS position, in the future?

It would indeed be interesting to make some experiments with Bluetooth-based GPS.
For that, we would need a Bluetooth base station to be connected to our PPM.

Willy

[Leon...]

Ηi to all.
We are (me and my team), among the first owners of the ppm Mark-ii system, and
we are very pleased with the attribution of this system.
This was also the reason that we took the new unit ppmIV.
With a few words ,perfect and at the same time very practical…

[Willy Bayot]

PPM MarkIV released

Hi all,

Our PPM MarkIV is now officially released and the web site has been updated accordingly.
Make sure you refresh the web page when you go back there in order to get the latest version of the page.

However, we have not yet published a price tag for its GPS option because we are still testing it. This should take one or two more weeks before we also release this useful option.

This is the link to our web site : http://users.skynet.be/fa352591/index.htm

Willy

[Willy Bayot]

A

Hi,

The latest software changes have given a huge improvement on the performance of our MarkIV system.
We have added a digital bandpass filter stage before the signal processing stages.
The net (proven) results are the following:
a. In the field, it is now possible to get very reasonable results with an UNTUNED sensor. We do not say that this what we recommend as normal operation mode but it is making the initial setup of the instrument much easier to perform by non-technical people.
b. With the tuned sensor, the instrument is now able to be operated inside a building and still give reasonably good readings.
c. Passing over a large, massive target does not anymore disturb the system, it stays synchronized and gives valid readings even if the signal magnitude naturally decreases with the high field gradients. This gave bad readings on the previous versions of the PPM.

All these experimental results go in the direction of making the instrument much easier to setup and operate. It was already very much immune against various electromagnetic disturbances but, now, it is much less sensitive to large field gradients.

This feature is obviously going to be integrated in the first available MarkIV systems as soon as it will be thoroughly tested.
Moreover, this feature will be made available as an upgrade to any existing user of the MarkII and MarkIII systems.

Willy

[Leon...]

Willy I have been following your project for a while now and think its one of the most outstanding projects in the treasure hunting scene. ............

Really, a essential instrument for the hunting of treasures.
In very low price.

[Willy Bayot]

Hi all,

We are now working on the new features we want to implement on our PPM instrument, it will be identified as 'PPM-MarkIV'.

The following add-ons will be available:
1. Automatic sensor tuning based on the local precession frequency.
On the MkII and MkIII, the tuning capacitors were put in operation through a manual DIP switch. On the MkIII, we had added an automatic procedure to measure the local frequency but the operator had still to setup the DIP switch at installation time.
On the MkIV, there will be a fully controlled tuning capacitor sub-system. Before starting a survey in a new region of the world, the operator will just have to push a menu key to execute the tuning procedure which will be entirely automatic.

2. GUI option module
This is a Graphical User Interface with Touch Pad based on an intelligent 3.5" QVGA module (see picture attached) replacing and upgrading the functions of the character-based LCD and five-key keyboard of the base unit.
Apart from its neater aspect on the control box (see picture attached), what can you expect from this option to add-on to the existing features of the MkIII or the base MkIV units?

• Easier Menu navigation
• Simpler system parameter setup
• Real-time graphical plot of the measured field gradients
• Review on screen of a captured survey grid uploaded from its SD Card file
• Integrated post-processing of a captured survey grid without any need to upload to a PC
• local 2D plotting of a post-processed survey grid with zooming and panning operations

This module will be an option on the base MkIV unit. Thus, the MkIV units will also exist in their base version using the LCD and Keyboard.
The already shipped units will be upgradable with this module.
This upgrade will be user-installable for MkIV units but will need a factory upgrade for MkII and MkIII units.

Willy

Hi all,

We have now received and tested a new batch of PPM-MarkIV boards.
These have the following extra capabilities on top of the ones of the MarkIII systems:
- GUI module option
- Controllable back-lighting of LCD for night operation (when no GUI option)
- Integrated GPS option (internal chip + patch antenna)
- Automated sensor tuning procedure based on the local precession frequency


Basic MarkIV configurations are immediately available. The price structure and the operator manuals will be updated in a few days.

The GPS driver and the automated sensor tuning control firmware code are still under test but the boards are designed and built to provide these capabilities.

Willy

[Willy Bayot]

More screen shots.

Look at the beginning of the progress event list there:
http://users.skynet.be/fa352591/index.htm

Willy

[Willy Bayot]

PPM MarkIV

Hi,

This is two pictures of the GUI in operation.
The first one is the real time display as a running bar chart.
The second one is the 2D plot displayed on the GUI after executing the post-processing locally.

Willy

[Willy Bayot]

Hi,

Thank you for your praise.
Our plans for the GPS are the following:
1. The GPS option has been coded and tested in the application code for a while now.
2. Our tests have shown that the RS232 level converter chip used to connect to a serial link to a GPS generates too much disturbances for our low-noise pre-amp and affects the signal quality. Thus, we need to connect to a GPS at the TTL level.
3. The standard NMEA data stream generated by GPS is un-interruptable and our sytem can not afford to hear this data flow while it is making its signal capture cycle. It can only accept that during its polarization cycles. Thus, we have designed our GPS driver to control a SIRFIII-based GPS as this allows for data polling.
4. On usual survey sessions for underground target search by a walking operator, we do not believe a GPS is necessary as a grid of survey lines is easily defined.
5. On underwater surveys, a GPS is required. We have designed and implemented a PC program to merge the data capture of the PPM and the NMEA data flow from the GPS of the boat. This program displays the resulting data as a 2D plot and stores it on a file.
6. We have designed on the controller board the option to fix a SIRFIII-based GPS chip with its integrated patch antenna but this has still not been actually tested. If our tests are successful, we could add this GPS option to our price structure.
7. We could as well make some testing on connecting a GPS to the GUI module through its second serial line using the NMEA protocol instead of connecting it to our PPM controller board, it is possible that this would not disturb the signal processing. This would then accept any external GPS to be connected if it supports NMEA protocol and connects at the TTL level.

I hope this answers your questions.

Willy

[Infamy]

Willy I have been following your project for a while now and think its one of the most outstanding projects in the treasure hunting scene.

How do you link in GPS? Do you have any plans to use mobile phones for GPS position, in the future?

[Willy Bayot]

Hi all,

We are now working on the new features we want to implement on our PPM instrument, it will be identified as 'PPM-MarkIV'.

The following add-ons will be available:
1. Automatic sensor tuning based on the local precession frequency.
On the MkII and MkIII, the tuning capacitors were put in operation through a manual DIP switch. On the MkIII, we had added an automatic procedure to measure the local frequency but the operator had still to setup the DIP switch at installation time.
On the MkIV, there will be a fully controlled tuning capacitor sub-system. Before starting a survey in a new region of the world, the operator will just have to push a menu key to execute the tuning procedure which will be entirely automatic.

2. GUI option module
This is a Graphical User Interface with Touch Pad based on an intelligent 3.5" QVGA module (see picture attached) replacing and upgrading the functions of the character-based LCD and five-key keyboard of the base unit.
Apart from its neater aspect on the control box (see picture attached), what can you expect from this option to add-on to the existing features of the MkIII or the base MkIV units?

• Easier Menu navigation
• Simpler system parameter setup
• Real-time graphical plot of the measured field gradients
• Review on screen of a captured survey grid uploaded from its SD Card file
• Integrated post-processing of a captured survey grid without any need to upload to a PC
• local 2D plotting of a post-processed survey grid with zooming and panning operations

This module will be an option on the base MkIV unit. Thus, the MkIV units will also exist in their base version using the LCD and Keyboard.
The already shipped units will be upgradable with this module.
This upgrade will be user-installable for MkIV units but will need a factory upgrade for MkII and MkIII units.

Willy