Help finding the correct way to wire a specific system

[quickmo]

Hey guys first of all Im completely new to electronics and also to this forum so Im sorry if I'm doing something wrong.

Here goes my doubt. Hope you can help me with this.

What happened:

I bought a darts board (ED310 Canaveral) with electronics that allow multiple players to play and show the scores, but someone broke the digital screen and it no longer works.

What I want to do:

I want to somehow connect the wires to receive the signal to an Arduino so I can get access to what numbers the player hit on the board on my computer so I can develop a software to show the results on the PC screen.

Problem:

I oppened the board and checked the circuit and I did not understood what is going on there. Can someone help me out what and where I need to wire to get the signals into the Arduino?

I took some photos of it, will attach to this post.

 

[rjenkinsgb]

I'd guess the connections from the dartboard are just an array or grid of switches.

The two connectors they go to appear to partly also connect to the extra buttons on the circuit board, so it's likely both the sensor and setup contacts are all read in the same way.

Look at how to read a keyboard matrix - eg. articles such as this:

Arduino Keyboard Matrix Code and Hardware Tutorial - Bald Engineer

A Keyboard Matrix adds a bunch of buttons to your project without burning up all of your I/O pins. Here's how to build a pushbutton matrix for an Arduino.

www.baldengineer.com

The harder part will be finding out which combination of connections each dartboard segment switch connects to...

I'd keep the section of the circuit board that has the sockets for the flexible cables and remove the area with the controller IC (the black blob).
(Don't try to connect to the flex cables other than by using the connectors on the PCB; the cable is rather fragile).

Fix the pcb somehow so the flex cables are not getting moved about too much or strained.


Then solder wires to all the connector pins on the underside of the board and label them all. Draw out a 10x10? grid on paper

It looks rather like one cable & connector are the matrix rows and the other connector matrix columns, so each switch should connect a wire on one connector to a wire on the other. Label the wires and paper grid rows/columns to match, eg. letters on rows and numbers on columns.

With each dartboard segment pressed in one at a time, go through the combinations or pins/wires to "map out" the switch to connector arrangement.

 

[quickmo]

Thank you for the response rjenkinsgb! So can I cut the section you told me like in the attachment I send now with no problems? And then wire each one of the lines I draw to Arduino? Or should I wire in a different spot of the board?

 

[Pommie]

On a darts board you have 20 numbers with three areas and the bull and outer bull, so would guess 62 areas. An 8x8 matrix would be the obvious way to go. Can you scope some connections to try and find some scan signals?

Mike.

 

[DrG]

you may want to check out this site http://obilhaut.freeboxos.fr/pydarts-wiki/doku.php?id=board_reconditioning and the related ones. They are about converting an electronic dart board to Arduino control (naturally). While that is not what you want to do, it looks like there may be some good interfacing information that you could use.

/soapbox on I used to play darts in a league in Grad school...every week. The league matches were scattered among the bars in the town...darts and ethanol...geez entertainment was so easy when you were young and could treat your body like an amusement park Never did get a ton-80 but I did get a few ton-40s. I have seen some of those professional matches on TV...don't know what else to say about that "sport"./soapbox off

 

[quickmo]

On a darts board you have 20 numbers with three areas and the bull and outer bull, so would guess 62 areas. An 8x8 matrix would be the obvious way to go. Can you scope some connections to try and find some scan signals?

Mike.

I didn't bought the wires and that stuff yet, I'm just absorving information before I do that. I'll try to follow what you guys said and if I get somewhere I post it here. Thank you!

 

[Nigel Goodwin]

Never did get a ton-80 but I did get a few ton-40s.

I got a few back when I used to play darts, including in league matches.

In fact we used to play in a very tough league, we played 701 (not 501), double start, double finish (not just double finish), just a single game each, and at full professional distance (most local leagues played a bit closer).

Anyway, best game I ever saw in the league was a member of our team, Roger Cooling, and he was really playing well and well ahead - then his opponent Nigel 'something' (forget his name now?, knew him since we were kids, and his dad was a darts friend of my dad) scored three 180's in a row - Roger just went to pieces, and Nigel won the game.

 

[DrG]

.... - Roger just went to pieces, and Nigel won the game.

Nice story (and memory). I remember playing cricket in a match where my partner was regarded as the best in the league. He knew our opponents well. They closed all numbers and we had two open. Instead of going for bulls, they chose to throw points (for non-players, hitting our open numbers resulted in points which we would need to make up at 25/bull). My partner was distinctly insulted by the move and immediately closed bulls. He instructed me, however, to close the numbers and to aim fat, meaning just make sure you get at least a couple of singles. He continued to pound bulls. While it took me 2-3 turns (can't remember exactly) to close two numbers, he had put us up some 200 points...and we won easily. Our opponents sulked away silently - quite enjoyable actually.

But, one must never lose all humility...I remember shooting trap once (and I learned to shoot only from spending time with a relative who loved it [ Reloadron, he taught me how to reload shells as well]. I hit 21/25 (still my highest score). I beat the squad (all relatives) and I was walking on air Later some hot-shots at the club went out and they were getting 25s AND were shooting from the hip (literally). I was watching and simply said "oh".

Later, I was revewing a US Army study on visualization techniques relating to performance and they were using marksmen as subjects. These guys (and Ron, correct me if I am mis-remembering) were winning tournaments 500-498 - those kinds of scores. After that, I said "Oh S___").

 

[Nigel Goodwin]

Nice story (and memory). I remember playing cricket in a match where my partner was regarded as the best in the league.

Well the best player in our darts league played for the Miners Standard pub, and had actually played in the News Of The World competition, which used to be one of the top professional darts competitions - and he'd never lost a game in our league.

Anyway, I ended up playing him - but as I mentioned previously, we played just one game of 701, double start, double finish - and it took him a few throws to get a double to start. Meanwhile I had started first arrow, and was happily scoring hundreds or so on my way down. Once he got started he was chasing me with 140's or so, but my lead was enough to get to a double first - which I hit with my first try

There was a deafly silence in the pub, as that was the only game in the league he ever lost - but it just goes to show, one game only and double start is a very tough game to play. Lucky it wasn't 'best of three' or I'd have been stuffed

 

[rjenkinsgb]

So can I cut the section you told me like in the attachment I send now with no problems? And then wire each one of the lines I draw to Arduino? Or should I wire in a different spot of the board?

Yes, just add wires to connect to the arduino.

Eventually also connect the main ground area (where RP1 and RP2 connect) to the arduino ground, but to start with I'd put all the wires to a bit or scrap stripboard, or just bare a short length on the end of each and tape them all to a bit of wood at eg. half inch spacing - some way you can easily move around the connections with a multimeter, to plot out which combination corresponds to which switch.


Or you can connect everything up and see what results you get in your program!

I'd say the upper row (with the resistor packs to ground) would be inputs to the MCU and the lower row outputs.

When waiting for a hit, set all the outputs (call them columns) high.
Any switch activation will then send one of the inputs (rows) high. When that happens, change to setting one output at a time high until you find the one that still sets the input high - you then have the coordinate of the activated switch.

You need to try all the outputs fast enough to see the switch still pressed, but with enough delay after each change before checking the inputs that the voltages have had chance to settle.