ESSENTIAL INFORMATION BUILD INSTRUCTIONS CHECKING YOUR PCB & FAULT-FINDING MECHANICAL DETAILS HOW THE KIT WORKS ADD AN AUDIO MESSAGE TO YOUR PRODUCT WITH THIS RECORD & PLAYBACK KIT Version 2.
Record Playback Essentials www.kitronik.co.uk/2149 Build Instructions Before you start, take a look at the Printed Circuit Board (PCB). The components go in the side with the writing on and the solder goes on the side with the tracks and silver pads. 1 PLACE RESISTORS Start with the five resistors: The text on the PCB shows where R1, R2 etc go. Ensure that you put the resistors in the right place. PCB Ref R1&R2 R3&R4 R5 2 Value 1K 4.
Record Playback Essentials www.kitronik.co.uk/2149 6 SOLDER THE LED The Light Emitting Diode (LED) should be soldered into the board where it is marked LED1. The LED won t work if it doesn t go in the right way around. If you look carefully one side of the LED has a flat edge, which must line up with the flat edge on the outline on the PCB. Once you are sure that it is in the right way around, solder it in place.
Record Playback Essentials www.kitronik.co.uk/2149 Checking Your Record Playback PCB Carefully check the following before you insert the batteries: Check the bottom of the board to ensure that: All holes (except the 4 large (3mm) holes in the corners and the interface connections) are filled with the lead of a component. All the leads are soldered. Pins next to each other are not soldered together.
Record Playback Essentials www.kitronik.co.uk/2149 Fault Finding Fault finding flow chart page 1 Start No - its on constantly, but dimly There is a dry joint on pin 11 of IC1. No - its on constantly Is the LED off? There is a short on pin 13 of IC1 Yes Press and hold the record button to record a brief message Did the LED light while record was pressed? Yes - but dimly Check R1 is in the right place.
Record Playback Essentials www.kitronik.co.uk/2149 Continued from page 1 Fault finding flow chart page 2 Press the play button Yes - but it was distorted, crackled or hard to hear over the noise Check C6 for a dry joint. IC1 for dry joints on pins 6 or 8. No - there was hissing Check For dry joints on R3 or R4. M1 for a short or dry joint. IC1 for a short on pin 4. IC1 for a dry joint on pin 12. C5 for a short. Yes - whilst the button was pressed There is a short on IC1 between pins 1&2.
Record Playback Essentials www.kitronik.co.uk/2149 Adding a Flashing Memo Recorded LED It is possible to use your Record Playback module as a memo, when doing this you might want to add a flashing LED to indicate that there is a recorded memo that should be played back. The kit doesn t include the parts to do this, however you only need a flashing LED and a slide or toggle switch to do this. The board includes an interface connector and this will be used to connect the LED and the switch to the batteries.
Record Playback Essentials www.kitronik.co.uk/2149 Designing the Enclosure When you design the enclosure, you will need to consider: The size of the PCB (below, height including components = 16.5mm) How big the battery holder is. These technical drawings should help you to plan this. All dimensions are in mm. 57 12 13.5 5.5 7 14 Interface LED 16 Mic 65 57 26 Speaker 39.5 17 4 4 8.5 20 4 x 3.
Record Playback Essentials www.kitronik.co.uk/2149 How the Record Playback Module Works Timing resistor Timing control Amp A2D Non-volatile Memory D2A Amp Microphone Speaker Device control ISD1820 Play switch Record switch Status LED The main component in the circuit is the ISD1820, which is a Record Playback IC. This is the main boxed section in the block diagram above.
Record Playback Essentials www.kitronik.co.uk/2149 Record Playback IC Pins on the ISD1820 The following table indicates what each pin on the Record Playback IC does: Pin No 1 Name REC 2 PLAYE 3 PLAYL 4 MIC 5 MIC REF 6 AGC 7 8 9 10 SPGnd SP+ Rosc 11 12 Vcc FT 13 RECLED 14 Gnd Description The record input: when taken and held high causes the device to re-record the message. The IC contains a pull down resistor on this input.
Record Playback Essentials www.kitronik.co.uk/2149 Using the Interface Connector The interface connector allows some of the more advanced options of the IC to be accessed. It can be used to connect off board switches for Record & Playback and gives access to the pins to play part of a message or use the looped play option. The status LED is output to the connector, as is the audio output signal, which can be used with a more powerful amplifier if required.
Online Information Two sets of information can be downloaded from the product page where the kit can also be reordered from. The Essential Information contains all of the information that you need to get started with the kit and the Teaching Resources contains more information on soldering, components used in the kit, educational schemes of work and so on and also includes the essentials. Download from: www.kitronik.co.
