Smart coaster project.

[Citizen 7]

Hi,

 

This is my first "serious" project.

I want to build a coaster, which will measure the  temperature of your cup (be it hot tea , cold beer or even fresh hot soup;) ) and  notify you  when it reaches you favourite value.

You know how it happens, you place  fresh  cup of tea  near your Leptop or TV and  because it is too hot to drink right away you want to wait few minutes.

But the internet or movie are so interesting  that you compltely forgot  about your drink. After you remember it is already too cold. And drinking warm tea or kakao is just disgusting:)

Sometimes there is THE perfect temperature for tea of coffee:)

 

 

That is why i want to  change to world! Here is my project

 

I take TI TIM006 for  contactless temp sensing,

MSP430F2002 or MSP430F2013 (depending on how much memory i will need) for main control

Another big feature is that the coaster is completely self powered;)

 I took TI BQ25504 for energy harvesting purpose  which is able to harvest  energy down to 50mV input Voltage (after cold start) and charge  a capacitor or a battery to 5,5 V!

The two solarcells  (52x38 mm) are enough to chage the 1 Farad Supercap.

On my table at common light conditions the charging process  is pretty slow, it can take about a whole day to charge from 2V  to 3,6V. Under the simple energy saving lamp it is a bit faster and  under the direct sun ( near the window) it takes just 10-15 min:)

I have  MSP430F2013 running from VCO a simple Timer/Counter in LPM3 and toggling  a pin  on compare interrupt. The voltage  on the storage cap  goes down at about 1 mV/minute. So a full charge  can power MSP for few hours;) But considering the fact ,that

[Fred 453]

That's quite an ambitious project, but it sounds like you've given it a lot of thought and planned it well.

[abecedarian 330]

Interesting project!

 

Wonder if you could use the heat from the cup / mug to augment power to the MCU using a thermo-electric generator?

[Citizen 7]

Interesting project!

 

Wonder if you could use the heat from the cup / mug to augment power to the MCU using a thermo-electric generator?

In fact I was trying to use peltier-element element to harvest energy at the beginning.

But the problem is to  establish a good thermal contact between a cup and Peltier. it came out that all cups and  plates have different shapes (if you look closely most cups have special shape on the bottom, to REDUCE thermal contact with a surface:)), and it is impossible to make one perfect surface for all of them. And dont forget with peltier you could only harvest energy from hot drinks, but what about beer?=)

After few tries with  different shapes made of  potting clay I decided to switch  to solar energy:)

[Citizen 7]

Hi,

 just a small update on this project:)

 

1. I managed to reduce power consumption from 220

[Lord anubis 1]

Cool project!

Eh this is hot,

 

You have a stalker here now.

[zlalanne 37]

Awesome that you reduced the current to 0.7 uA! If you are using the CCS compiler try using the ULP adviser to see if there is anywhere else in your code that would help achieve lower power. I think the switch to a battery makes sense, although the solar part of it does seem cool.

[Citizen 7]

Awesome that you reduced the current to 0.7 uA! If you are using the CCS compiler try using the ULP adviser to see if there is anywhere else in your code that would help achieve lower power. I think the switch to a battery makes sense, although the solar part of it does seem cool.

Hi,

I doubt I can reduce  current consumption, according to the datasheet, the  current in LPM3 is about 0,7

[Citizen 7]

Hi,

for those, who think the project is dead: no it isn't! I just had my exams, but the development goes on;)

Here is the current progress:  I  hooked everything together, programmed communication between  TMP006- Sensor and WS2812-LED. Right now everything  is working as intended;)

The next step is designing the PCB and i am working on it right now;)

 

The  system consumes  about 0.4-0.5

Edited August 28, 2014 by bluehash
[ADMIN] - Image uploaded to 43oh. Please attach your images to 43oh. Please!

[bobnova 59]

I like this concept. I am constantly forgetting my too-hot-to-drink drinks until they're far too cold.

I'll definitely be following this project!

[bluehash 1,581]

PS

I am still having problem  powering LaunchPad from battery, dont know why, the MCU  behave very strange,

@@Citizen What sort of problem.

Good progress!

[Citizen 7]

@@Citizen What sort of problem.

Good progress!

Thanks. I had a problem, that  touch buttons didnt function as intended with battery . But I solved it:)

[Citizen 7]

Hi there:)

 

Finally  the PCB's are finished and ordered

 The coaster consists of two PCB:

1:  Main PCB (5 cm x 5cm) with 3 Touch buttons  on Top and  electronics  on Bottom. The Plexiglas covering will be  glued directly on top of it.

2: Secondary PCB (1.7 cm x 1.3 cm) will carry the TMP006-sensor and WS2812 LED. It is mounted on the bottom of the Main PCB. In this way i am able to place the LED and sensor directly under the plexiglas.

 

I noticed  that if the battery voltage drops under  2,6-2,7  V the  blue LED doesn't work. That is why i added Ti TLV61224 booster (yey , i love Texas Instuments:) to get stable  3V for nice bright LED independently from the battery voltage. I also switch this converter on/off  via BS138 MOSFET, otherwise it  drains  precious 500

[bluehash 1,581]

Hi there:)

 

Finally  the PCB's are finished and ordered

 The coaster consists of two PCB:

1:  Main PCB (5 cm x 5cm) with 3 Touch buttons  on Top and  electronics  on Bottom. The Plexiglas covering will be  glued directly on top of it.

2: Secondary PCB (1.7 cm x 1.3 cm) will carry the TMP006-sensor and WS2812 LED. It is mounted on the bottom of the Main PCB. In this way i am able to place the LED and sensor directly under the plexiglas.

 

I noticed  that if the battery voltage drops under  2,6-2,7  V the  blue LED doesn't work. That is why i added Ti TLV61224 booster (yey , i love Texas Instuments:) to get stable  3V for nice bright LED independently from the battery voltage. I also switch this converter on/off  via BS138 MOSFET, otherwise it  drains  precious 500

[Citizen 7]

Hi, Thanks  for the article on the frontpage!

Yes, the buzzer is new addition, since  i have to inform the user his drink is at optimal temperature.

 

PS

The energy harvesting feature was only present on the first prototype, later I decided against it, since  it will raise  self costs and demand more complicated design;)