Interactive Cell Board game

Finally I’ve gathered all the components and mounted the first full prototype of the board game (I already did some test previously to validate the SPI led drivers in First prototype of the electronic board game Helvetios). The component shortage has delayed the mounting by 6 months until I’ve got some critical components, mainly the led driver TLC5947 and the DC/DC regulator TPS561201.

Initially I contacted some pcb companies from China to fully build the prototypes, but the cost of the components at the start of 2022 was way too much. So I ordered only the PCB and the bottom stencil in JLCPCB, and then I gathered the components until have them all so I could build the circuits by myself.

I did the mounting by hand (in the absence of an SMD oven as the I used for the circuits in the LifeLinker), using soldering paste, a hot air soldering station and a lot of patience. To solder the bottom side I used a stencil so it’s were there are more integrated circuits and some with thermal pads like the led driver. This way the solder paste distribution would be much better.

The circuit was designed to be content in size so the first prototypes would be more economical due the pcb price and the necessary acrylic sheets to make the led difusor and the cell separator. This way we could program all the firmware to control the leds and the USB communication. The next designs will follow the concept of row circuits as explained in Helvetios. This way we could make boards with more and bigger cells.

Some pictures of the mounting process:

To start the prototype I used a development board NUCLEO-F103RB, which I already used in First prototype of the electronic board game Helvetios. This time I used the development board to program the circuit, using the connector that allows to program other circuit by using the SWD communication. This way I could connect to the electronic board game and debug the code for the led drivers and the Hall sensors:

Besides the development board I used a little 8 channel 24MHz logic analyzer. With this device and the software Pulseview from the Open Source project Sigrok is easy to see which signals are generating and check the correct addressing of the led drivers. Also you could decode some protocols as SPI and I2C, and is very useful to determine the refresh speed of the system.

When testing the code I also tried some led diffusers:

And finally a video showing the cell detection and some color examples:

These last months I’ve been finishing the design of what will be the first circuit of the electronic boardgame Helvetios. It has been a little slow process, due doing it in my free time but mostly due doing it in only one circuit to save cost. In later designs I will continue with the concept of circuits of rows of cells, connected between them. This will allow bigger boards and with more and bigger cells.

The design of this boardgame have 91 cells, and it will be used to develop the control firmware. This software will manage the RGB lightning of the cells, the magnetic Hall sensors and the USB communication with the game master circuit.

In the bottom layer there are the connectors. It has an input power supply connector, a micro USB to communicate with the game master circuit, and a power supply output connector to supply this other circuit.

Now starts the manufacturing process of the circuit, that will also be complicated due the lack of component supply situation. It’s very possible that I could not get some critical components like the led drivers or the microcontroller in all this year 2022. The lead time is 2023 for some of them. Also the fact that the circuit has components in both sides implies that not any factory could mount them, it needs to reflow process to solder all the components.

I will use this this board circuit assembly time to develop the game master circuit, and make designs of the enclosure to house the circuits. So the next updates will be about how I’m doing designing this game master circuit, that will have a raspberry Pi Zero, an oled screen and a button interface so the user could choose the actions and movements. I will also advance some of the boardgame software, mostly the USB driver to test the communications with the Raspberry.

Well, I've finished the schematic so I've started to place the components. It will take a while due there are 559 components in total, with 273 LEDs.

And this is the A4 prototype with only 91 cells, I have drawings of other bigger designs with 169 cells and even 505 in a 70x70cm board!
This is made in only one circuit due the small size of the boardgame, for bigger boards I'll use smaller circuits as 'rows' and connect them, so it will be easier to design.

I've made a laser cut prototype of the board. It's the led diffuser an the top face of the board. I will start to a 91 cells board, due it fits well in a A4 sheet and I could make a single PCB with all the electronics. This will help to develop the software, later it could be escalated to bigger boards with more cells and grouping cells to simpler pcbs interconnected.

This design will be a single board with all the sensors and leds. The microcontroller will have an usb connector to manage it from the raspberry or other system.

I've cut also what will be the interface to the board, a little oled screen and some buttons to select and navigate the boardgame cells. This interface will be connected directly to the Raspberry Zero

Also I've been busy making the schematics, now It's time to component placing and start to route the pcb.

I will add later the schematics when are finished.