RobG

Products using MSP430

98 posts in this topic

Interesting tear down.  I did DIY bicycle tail lamp using MSP430 back in 2011. Still working. Using 2xAA Alkaline cells. Running for more than 3 months in the battery. 3x4 red LEDs. BC107 transistors. One push button switch. Sleep in LPM4. LED driving from PWM. I have't measured the currents.

20 uA is too much!  :(

tripwire likes this

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@@pneumatics Looks very similar to the IKEA toy kitchen modification I did. but that sports two sets of 3 LEDs and two push buttons. It sleeps in LPM4 too.

The toy has a timeout of about one minute though, which I made using the watchdog timer and LPM3. I go back to LPM4 when the watchdog timer is not used anymore (ie: when no LEDs are on).

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Bike light follow-up: reverse engineering time!

 

here is my almost complete circuit diagram.

 

IC1 is a voltage regulator: 2.5V, exact type I could not find out. Only the MSP runs on the regulated voltage, all the rest runs from the raw battery voltage.

 

Voltage divider R2 1M / R3 330K measure the battery voltage (some microamps get lost here)

 

LED2 and 3 are indicator (red/green)

 

LED1 is the power led

 

PWM is 20kHz, coming from pin 11 of the MSP.

Main switch is a Si4562, N and P channel 20V 5A mosfet. Inductor is 100uH.

Instead of using only the upper fet, they alternately switch on the upper / lower FET, avoiding one diode voltage drop, increasing effiency.

The circuitry around IC3 (a weird CMOS 4572) creates a small dead time (less than a microsecond) to avoid cross-conduction.

Note the resistors in the signal path ;-) 

 

They managed to regulate the LED current without a shunt resistor. Took me some time to find out how:

The voltage across the inductor is low-pass filtered, R14 390k / C4 0.1u, then fed into the MSP. Of course the DC-part of the inductor voltage depends on the current flow.

Pretty clever. The regulation is rather slow (ramp-up of current is so slow it is actually visible).

 

The circuitry around Q8 and Q9 takes care of the battery charge turn on/off. Input is from a wall-wart adaptor which is 500mA constant current type.

R10/R11 tell the MSP that external voltage is present.

 

 

post-37272-0-41842600-1450548783_thumb.png

gsutton, tripwire and bluehash like this

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Nice work reverse engineer  :)

I'm not that much familiar with buck/boost converters. So I could not understand the inductor part. So we will leave it aside for the time  :D.

I have a question. The light has 4xAA cells, right? So can we tap from 3V (ie 2xAA) point and power the MSP? I'm (planning to) doing that in my working project. I dont know whether it is correct. The drawback i'm seeing  is that the battery may drain unequally. But uA and nA counts for Alkaline cells?

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sure  you can power an MSP430 from 2 AA cells. The unequal power drain should be manageable for a hobby project. 

However, for a "product" it is probably not a too good idea: 

- what happens when inserting / removing batteries?

- 2 cells discharged during months, 2 others not, might be o.k. for alkalines, but for long term using Nimh? I do not know.

- The MSP can use the internal reference for battery voltage measurement. You have to check the datasheet whether the 1.5V reference

works when 2 cells are at the end of life.

- you might also check for wrong polarity. The german clever designers solved this issue mechanically. It does not give contact when in wrong direction.

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Philips Hue Tap, a wireless light switch without battery, featuring a MSP430FR5730

post-9974-0-22712100-1463954648_thumb.png

 

Teardown by Adafruit, with the MSP430 discovered at the 15 minute mark.

https://youtu.be/4T4nhuobjZM?t=875

 

This device doesn't have a battery, but uses a mechanical, relais-like component to generate power when the user pushes buttons.

https://www.enocean.com/en/enocean_modules/eco-200/

post-9974-0-07075900-1463955396_thumb.png

bluehash, dubnet, spirilis and 2 others like this

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Here's a MSP430F413 in a cheap (< US$100) radar speed gun

post-9974-0-18307200-1471988698_thumb.jpg

http://www.allaboutcircuits.com/news/teardown-tuesday-radar-gun/

 

I'm surprised how little analog and digital processing there is in this product.. I guess all the RF magic happens inside the transceiver module (which is available at Mouser for $50).

bluehash and spirilis like this

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Another MSP430, this time it's a MSP430FR5739 running the Ring "smart" doorbell :rolleyes:

post-9974-0-14687500-1485365700_thumb.png

 

The full teardown is documented here:

https://www.exploitee.rs/index.php/Ring_Doorbell

 

I was a bit surprised to only have a "lowly" MCU in a device that streams video over WiFi. But it looks like a specialized IC by Omnivision (OV788) and the WiFi module (GainSpan GS2011M) do the grunt work. The MSP430 probably just waits for someone to press the button and then turns on LED driver, camera and WiFi. See this dev kit by the vendor of the WiFi module.

http://www.gainspan.com/products/gs_adk_aek_videoov720p

post-9974-0-05618700-1485366731_thumb.png

The wonders of integration.

 

TI has a similar app note pairing the OV788 with a CC3200.

http://www.ti.com/lit/ug/tiduck9/tiduck9.pdf

 

 

 

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A MSP430F415 in a cheap fingertip oximeter from AliExpress

post-9974-0-86459300-1486761037_thumb.jpg

post-9974-0-35348100-1486759392_thumb.png

 

Teardown here: http://www.kean.com.au/oshw/oximeter/

 

I wonder if that nicely labeled JTAG header is still functional.

post-9974-0-05590900-1486759403.png

 

With 16K Flash and 512 bytes of RAM, this MCU is comparable to the MSP430G2553. Energia on an oximeter anyone?

 

Addendum 2/28: I ordered an identical looking model off AliExpress. Unfortunately, it's no longer MSP430 inside :-( It's now powered by a STM32F030 ARM M0.

oPossum and Fmilburn like this

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I went to Sears yesterday to get my new lawn mower and I got a free gift, Kenmore Alfie Voice-Controlled Intelligent Shopper.
The regular price of Alfie is $49, but they are now on sale for $25. However, if you are SYW member and you spend more than $25, you get one for free (expires 7/1/17!) 
BTW, I also found Alfie for $7.95 on Amazon (with free Prime shipping, even cheaper from other vendors.)

What's the big deal about Alfie? Crack one open and you will find the following:
CC3200R1 Single-Chip Wireless MCU (with W25Q32JV (32M-bit) serial Flash memory from Winbond and a chip antenna)
TLV320AIC3100 Low-Power Audio Codec With Audio Processing and Mono Class-D Amplifier
3.7V 500mAh LiPo battery
12 WS2812B LEDs
Other useful things are microphone, large speaker, 2 LEDs, 2 switches, and USB port

In other words, IoT experimenter's treasure chest!

Can't wait to hack that thing (there's what appears to be programming header on the board.)

 

 

 

alfie.jpg

top.jpg

alfie inside.jpg

bottom.jpg

dubnet, Rickta59, Fmilburn and 1 other like this

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It even says ZEK on the CC3200!

It must be calling me.

B)

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I didn't even know they existed until I read your post!

Maybe I can use a freight forwarding service?

Hmmmm....

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