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Target Sensor

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Andreas Olsson edited this page Jul 10, 2023 · 3 revisions

The target sensor is the one that is connected on each shooting targets.

You need to use an USBASP for ISP programmer like this one Pins on the programmer need to be:

  1. MOSI
  2. 5V
  3. X (Not in use)
  4. X (Not in use)
  5. RESET
  6. X (Not in use)
  7. SCK
  8. X (Not in use)
  9. MISO
  10. Ground

Never use external power when the SPI programmer is connected!! The SPI Programmer will give power to the target board it self.

How it's designed

The board has jst connection for the almost everything. And if you need some other functions there is extra pins avalible to use.

The leds

There are 4 leds on the board. You have the standby led and charge led, they are only for the charger. The charge led will light during charge, and when the charge is done it will switch over to standby led.

PWR/BATT led is so you know you have the power on. Also it will blink when running low on battery. The Target led is to light up when the target is active. Please read more about the external sensor about the target led.

NRF Module

The bord has been tested with both type of NRF24L01 modules. The one with internal antenna and the one with external antenna. For longer range use the one with external antenna. Just plug it in the U5 on the pcb. The NRF module gets 3.3v

Shake Switch & External Sensor

This board don't have any place for soldering the shake switch (Vibration sensor) as i don't recommend to have it strait on the target. Instead there is an jst connection for the shake switch you can use. One pin goes to A0 and one pin goes to VDC. I recommend to use the hard version or medium.

If you are going to use the target led on the pcb connect the vibration sensor to the Shake Switch jst. If you would like to have the target led also on the target you can use External Sensor instead. From left to right there is this pins:

  1. AO (For shake switch)
  2. D5 (For Led)
  3. VDC (For shake switch)
  4. GND (For Led)

Battery & Power

The battery jst has following pins:

  1. Batt +
  2. Batt - Use only lipo batterys!

5v In is for charging. Only charge with 5v. Pins are:

  1. 5v
  2. GND

PW Switch is for turning on the target. It get's it power from the battery it has the following pins:

  1. VDC
  2. Batt +

How to use Piezo for vibration

It is possible to use Piezo element for vibration sensor. You need to use the External Sensor jst connector. You need to add a 1M Ohm resistor between piezo vcc and ground. Connect the VCC on piezo to A0 pin and the ground to ground. The code is the same to use. You can read more here on how piezo element works with arduino.

How to use Digital Shake Switch

You can use a digital shake switch also, you need to do some changes in the code because they only send high or low. Use any free digital pin and power it thru VDC and ground. Read more about it here.

How it's works

The target listen for unique ID numbers that the main unit will send out. If it is the right number, they will activate the hit mode and light up target led.

Now you can hit the target. In the code there is a safe mode built in, if you don't hit for 15 secounds, the target will leave the hit mode and return a miss signal to main unit. The time can be changed. If you hit the target, the main unit will get the info and inform the next target.

The NRF Module

The NRF module works on 2.4 GHz and can work on long distance. The NRF24L01+ Module has longer range (up to 1000 meters) and uses external antenna. The normal NRF24L01 module has internal antenna but i think it's the best one if you not going to have your targets far away.

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