In this article I would like to show an updated path for version 3 of the AZ-Touch Mod wall housing set, as of March 2023.

Due to my increased work with the AZ-Touch Mod wall housing set with 2.8 inch touchscreen, the desire to use the installed SD card slot of the display. Our author Gerald Lechner gave me the tip, his Blog on the subject to take a closer look at. I noticed that the article referred to an old version of the AZ Touch Mod and could therefore only serve as a template for my current project.

Hardware for this blog

For this blog, the AZ-Touch Mod wall housing set is a must, see Table 1.

POS	Number	Component	link
1	1	AZ-Touch Mod wall housing set	https://az-delivery.de
2	1	Optional ESP32 NODEMCU Module WiFi Development Board	https://az-delivery.de

Table 1: Hardware for this blog

In addition to the actual Wandmod, you need further tools and material to recreate this blog, see:

POS	Component
1	Soldering iron with solder
2	The bell wire, preferably in different colors
3	Bush and pen strips
4	Winked up pen strips
5	Tongs
6	drill
7	Tool and material to crimple your own cables

Table 2: More material

Current status of version 3 of the AZ-Touch Mod

A lot has happened on the board compared to the previous versions with the update to version 3 of the AZ-Touch Mod Wall houset set.

1. The buzzer for tones has disappeared
2. Some components were replaced cleverly
3. The 2.4 and 2.8 inches can now be put on a circuit board, before it was a separate board
4. The basic layout has changed
5. The Nodemcu has been removed in version 3, now there is only the ESP32 Dev Kit and the D1 Mini
6. Version 3 has access to the Pins of the ESP32 and ESP8266

Points 3, 4 and 6 in particular are interesting for this blog, since the path described above by Gerald Lechner is a little easier. However, you still have to solder and also crimple cables for plugs. Anyone who is not afraid of this work or knows someone who has the necessary manual skill will be able to use all the advantages.

Solder SD pins

In the old version of the AZ-Touch Mod Wall housing set, you had to bend and solder a PIN of the socket bar. This point is omitted by the new layout of the board. The easiest way is to take a close look at Figure 1.

Figure 1: Undernite circuit board with painted pins for SD card

If you insert the socket strip at this point, the display with soldered pen strips fits perfectly together, see Figure 2.

Figure 2: Display on the circuit board, in front of the soldering

It is best to assemble the display at the intended stops and then solve the pen and socket strips.

You have the connection from the board to the display. However, later communication for the ESP32 Nodemcu modules is still missing. At this point you use the not soldered contacts for the display, see Figure 3.

Figure 3: Use pins of the unused TFT display

As shown in the picture, solder a angled pen strip from the sixth pin from above. The eighth pin has been deliberately served because it is not needed. Solve out two other angled sockets on the side of the microcontroller at the IO32 - IO33 and A0 - IO39. Finally, solder the pins of the cables shown, see Figure 4.

Figure 4: soldering the pins of the SD correctly

Table 3 should explain the exact wiring again as an aid. The orientation from Figure 4 is important for this.

POS left from above	function	POS right from above	function	remark
1	Sd_cs	%	%	Is not soldered at the TFT
2	Sd_mosi	6	Tft_mosi
3	Sd_miso	9	Tft_miso
4	SD_SCK	7	TFT_SCK

Table 3: Connection of the pins

As it may. have already recognized on Figure 4, the first PIN SD_CS is inserted in my example at IO 25. This must be observed in the later source code, otherwise access to the SD card fails.

Microcontroller in a closed AZ-Touch Mod Resetten

I now come to another modification that I made in the course of my upgrade.

If you take a closer look at Figure 5, the small button will be noticed on the left side.

Figure 5: Reset button on the AZ-Touch Mod

I installed this in order to be able to carry out an externally initiated reset. I had the problem that the SD card had always had problems with the first start. Specifically, this means that the SD could not be initiated and the microcontroller had to be restarted once. At this point I would probably only have to make a few adjustments in the source code, but such an external reset is also practical in other moments. If you search for "7 mm mini round momentary 2 pins" at a large online shipping trade, you will receive the button I have built into a search result. With an 8mm drill I drilled a hole in the housing in the position of Figure 6.

Figure 6: Position of the hole for the button

Make sure that the hole may be at a stiffening rib on the inside of the housing. You have to remove this rib with a small pliers, otherwise the button cannot be screwed clean later. The wiring is now a bit more complicated. To reset the microcontroller, the PIN must En be pulled to mass. For the mass, a wire from the button onto the PIN can Gnd the circuit board is inserted, but the second wire must be directly on the soldering pin for En be soldered, see Figure 7.

Figure 7: wire soldered directly to pin en

Since it has to be soldered directly on the socket strip, see red cable, it is advisable to prepare the contact and the open strand with sufficient solder. If everything is soldered and the button is installed, the remaining cable can be stowed away below the display. This means that the button does not have to be dismantled from the housing every time when removing the board.

Conclusion

The conversion shown here is possibly. A little more complex than the one that Gerald Lechner described. With the current version 3 of the board, however, you now have a somewhat lighter solution to use the SD card and access further IO’s.

At first it cost me some time to check what is possible, but Gerald Lechner's basic work was a great help. So if you want to take full advantage of the AZ-Touch Mod wall housing set, you should think about this upgrade.