# Any guesses on what microcontroller is used in toy cars? What would be a good replacement?

#### bcl79

Joined Nov 10, 2019
2
My son has a toy car, similar to the one in the link below, that no longer works. The IC is covered in epoxy. Any guesses about what it could be? What would be a good replacement? The car has buttons that make it drive forward, play music, and turn on lights. Also, I realize the easiest/cheapest route is to replace the whole car but my 4 year old son is not rational and I like tinkering with things. Thanks!

#### ronsimpson

Joined Oct 7, 2019
173
We could guess, with a clear picture.
If you worked at $1.00/hour it would be cheaper to get a new car. He will be 5 or 6 before you get it done. I know! #### MaxHeadRoom Joined Jul 18, 2013 19,186 Ebay for between$10 - $30. RC to boot! Max. #### AlbertHall Joined Jun 4, 2014 8,527 The IC is covered in epoxy. If it looks like the picture below then you cannot replace it. #### DickCappels Joined Aug 21, 2008 5,943 This would be very challenging to simulate on a different controller. The main problems are: Music -not easy unless you experience in this kind of application. The remote control protocol -how would you find out what it is? If you are already familliar with a microcontroller family use a part from that family, otherwise you will probably spend many hours learning the chips and tools before even getting started. I vote with the others -it is probably much more practical to get a new one. #### djsfantasi Joined Apr 11, 2010 5,703 It is unlikely that the microcontroller is a consumer level product that could be replaced. It is likely that it is a custom chip designed just to perform the tasks the toy car needs. Since it’s a custom chip, you can’t purchase a replacement. You can’t fix it b #### MaxHeadRoom Joined Jul 18, 2013 19,186 The car has buttons that make it drive forward, play music, and turn on lights. Also, I realize the easiest/cheapest route is to replace the whole car but my 4 year old son is not rational and I like tinkering with things. Thanks! Looks like it is not R/C as I originally thought but operates from four buttons on the roof. (re Utube video). Many time it is the P.B. contacts that malfunction with use, you can check and see if they will clean of any residue if this is the problem, there are whole insert kits on ebay. Max. Thread Starter #### bcl79 Joined Nov 10, 2019 2 Looks like it is not R/C as I originally thought but operates from four buttons on the roof. (re Utube video). Many time it is the P.B. contacts that malfunction with use, you can check and see if they will clean of any residue if this is the problem, there are whole insert kits on ebay. Max. Correct, it is not R/C. Before I made my original post, I disassembled it and cleaned the contacts and inspected all the components I could see. I resoldered two connections to LEDs and fixed where the power supply wiring had been crushed. The crushed wire was still working but I thought it best to fix it. Everything else looks fine. If it is a custom chip then fixing this is much further beyond my skill level than I expected. Thanks for all the feedback. #### dendad Joined Feb 20, 2016 3,084 If you have room, it could be a good starter project for an Arduino. The Nano is relatively small, but a motor driver would be needed too if the car does not have one. Or an ESP8266 that would give you WiFi control. https://randomnerdtutorials.com/ is a great site for learning about them. But there is a huge amount of info on line. #### MaxHeadRoom Joined Jul 18, 2013 19,186 Looks like the recording is only for 10 or so secs, there is audio IC recording IC.s that will record 10+ sec for about$2.00 on ebay. ISD1820
It could be dubbed off of the Utube audio.
Max.

#### Wolframore

Joined Jan 21, 2019
1,321
I took apart my optical mouse which kept connecting and disconnecting. After about an hour or so... I traced it to the connection. Took the pins out. Nope. It was the wire... had to cut it and splice it back. No clue why I didn’t just get another mouse... it’s nice to fix things. For weeks I thought it was a Windows/driver issue. Its easier to get work done when your mouse does not have it’s own mind.

Fixing things and even designing usually costs more than just buying something... its not the only reason for tinkering.

if you want to fix something like that, it’s possible to just replace the whole thing with a little microcontroller and even add features to it. I wish I had more time. I see so many toys for my grandkids that I want to add things to. It wouldn’t cost much in parts... some time involved in programming but some of us find enjoyment in this... like a puzzle...

as stated the most challenging part would be to add sound... sound take a lot of memory, power and additional components depending on how it’s done..

also challenging would be design all this to find into that tiny car. Don’t expect a fix in a day might be what others are saying.

#### BobaMosfet

Joined Jul 1, 2009
836
Correct, it is not R/C. Before I made my original post, I disassembled it and cleaned the contacts and inspected all the components I could see. I resoldered two connections to LEDs and fixed where the power supply wiring had been crushed. The crushed wire was still working but I thought it best to fix it. Everything else looks fine.

If it is a custom chip then fixing this is much further beyond my skill level than I expected. Thanks for all the feedback.
That is not a random epoxy covering the chip to hide what chip is used, that _is_ the chip. It's called a 'blob chip' (technical 'COB' which is 'Chip On a Board'). They use a blob to protect it instead of an actual IC, because it's cheaper to do so in manufacture.

If you send an actual picture of the blob-chip and surrounding PCB, we _might_ be able to tell what it is.

Joined Jul 18, 2013
19,186
as stated the most challenging part would be to add sound... sound take a lot of memory, power and additional components depending on how it’s done..
The ISD1820 will record and playback up to 20sec, which according to the Utube video is ample.
Max.

#### Wolframore

Joined Jan 21, 2019
1,321
The ISD1820 will record and playback up to 20sec, which according to the Utube video is ample.
Max.
oh this could be a fun way to hack things into old toys... is it any good? Is it class D PWM? What's the bandwidth?

Ugh it's dismal but it's inexpensive... I like something closer to 10-15 k bandwidth please.

Joined Jul 18, 2013
19,186
oh this could be a fun way to hack things into old toys... is it any good? Is it class D PWM? What's the bandwidth?

Ugh it's dismal but it's inexpensive... I like something closer to 10-15 k bandwidth please.

View attachment 191231
Basically used in toys, not for Hi-Fi reproduction, you can improve it slightly with a LM386 on the output.
I just used one for my portable remote door bell receiver I hooked up an old garage door transmitter to the door bell operator.
Max.

Joined Feb 20, 2016
3,084
I have used the WT588D boards. They will run quite well on their own, driving a speaker. And draw very little current when not running so no power switch is needed. The small modules need 4 push buttons to trigger the sounds, or can be run from an Arduino or similar, to have many sounds.
The boards are around \$3 each.
https://www.ebay.com.au/itm/1PCS-WT588D-16p-voice-module-Sound-modue-audio-player-for-Arduino/352569237860?hash=item5216c3a164:g:cT4AAOSwP85cPXSq

A programmer is needed,

or a larger model with built in programmer.
https://www.ebay.com.au/itm/Voice-WT588D-U-Voice-Module-5V-Mini-USB-Interface-Sound-Module-16M/401394055742?hash=item5d74f33a3e:g:DVgAAOSw7htZpjOF

I made a model train station announcement device for my granddaughter's other grandpa.
And a laser tag gun with multiple gun shot sounds and status messages.
These boards are well worth a look.

Here is an Instructable on the USB version...
https://www.instructables.com/id/WT588D-Standalone-Arduino-sound-player/
(I probably do not need to add pictures as now the site shows those in the links)

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#### Wolframore

Joined Jan 21, 2019
1,321
10k isn't hi fi - and 3k would be fine for sound effects I suppose... I'm a little picky with sound. I was at the hobby store the other day the little HO gauge DCC trains are running sound now... it sounded better than 3k bandwidth tho.

#### djsfantasi

Joined Apr 11, 2010
5,703
10k isn't hi fi - and 3k would be fine for sound effects I suppose... I'm a little picky with sound. I was at the hobby store the other day the little HO gauge DCC trains are running sound now... it sounded better than 3k bandwidth tho.
Not just the little HO trains. N Scale trains (~1/2 HO) also come with sound.

You don’t use a transformer to run model trains anymore. The National Model Railroad Association has published a standard for Digital Command Control. There is a constant DC voltage across the rails at all times. A digital signal is imposed on the rails, which is decoded by a module inside the engine. Besides speed and direction, the modules control front, rear, ditch lights and sound. The spec includes optional lights and accessories to be controlled as well. Other decoders connect to the rails, and control track switches, signals and even lights in the scenery.

The decoders are wicked small. Maybe 1/2”x 1”?

#### Wolframore

Joined Jan 21, 2019
1,321
@dendad that looks like a very useful chip... I have a few projects that could use this. It looks like a lot of fun.

@djsfantasi - how's your museum coming?

#### djsfantasi

Joined Apr 11, 2010
5,703
@dendad that looks like a very useful chip... I have a few projects that could use this. It looks like a lot of fun.

@djsfantasi - how's your museum coming?
Museum? I’m working on local versions of premium theme park attractions.