[Originally published in a series of posts in 2005 on the original S9Y hosted version of this site the posts have been combined, edited, and retro dated. — jv]
The solar powered Altoids tin! This is a Geocaching Travel bug TBHC3P launched in 2005 it was still showing life when last logged in 2009. It survived the Waco flood of ’07 and traveled 5509 miles to texas and back.
This is the completed bug:
This second bug in the series is currently under development and taking shape. The design is based around a PIC microcontroller chip which increases the intelligence of this bug. Like the first bug the primary mission is to blink a blue LED. Number 2 also includes solar power and somewhat intelligent power saving when dark. It is also programmed to chirp and blink additional LEDs when it is found in a geocache or when it is put away from the light.
Features and Behaviors:
- Solar powered for extended mission life.
- Rechargeable internal lithium ion battery. Without actually testing or doing all the math I estimate that the bug can run dark for at least a month, perhaps more.
- Electrolytic capacitor for backup operation. If the main battery pack dies it can be unplugged to allow light operation and a few minutes of dark operation.
- Light operation the bug blinks a blue LED about every 4 seconds and emit a double click.
- In dark operation it will blink about every 13 seconds and emit a single click
- Transitioning from light-to-dark it emits sad chirps.
- Transition from dark to light triggers happy chirps.
User operation:
- Open the lid and examine it.
- Take it with you while in your care and try to keep it in the light (solar panel up) as much as possible to charge.
- Try to place it in safe and dry caches that have a lot of traffic. The bug doesn’t like to hide for too long.
- The bug doesn’t like extreme cold so it would prefer to migrate South for the Winter.
Here is the source code. It was cobbled up from some example I googled for when I was first playing with PICs. I don’t have the link any more.
Almost all of the parts for this were scavenged out of my junk boxes except for the solar cell ($5) and the PIC chips for about $3 from Jameco. The programmer was a $10 ebay special and the MPLAB assembler and IDE is a free download from Microchip. The signature Blue LED is scavenged from glucose meter and the lithium battery is from a no longer function digital camera.
I figured out the divider to sense the light ok. I found about 2K/10K worked fine. Of course when I added real components to the circuit I tried to use 10K/100K and it didn’t work. I haven’t debugged it yet but either I fat fingered the soldering or it doesn’t allow enough current to pull the pin high. I scaled the network up to reduce current but maybe I went to too far.
I made two feature changes to the hardware. The first was to remove the red LED which I wasn’t really using and use the hole to mount the travel bug ID tag. It is screwed in now but I will probably solder the screw to prevent it from loosening. The other change was to keep the BFC isolated from but parallel to the battery. I need to add 4 more diodes and rewire some stuff but I think the fugliness of the construction will be worth it. This way the battery can die and the circuit can still operate on solar/capacitor power.
I hope to achieve the lowest power consumption by spending most of the real time in SLEEP mode which only draws a few microamps. When it is running I have it clocked with a low power 32 khz tuning fork crystal. This is sufficient for what it needs to do where the most demanding task is beeping a piezo speaker.
LIST P=16F84A;f=inhx8m ;_CP_OFF equ H'3FFF' ;code protect off ;_PWRTE_ON equ H'3FFF' ;Power on timer on ;_WDT_OFF equ H'3FFB' ;watch dog timer off ;_LP_OSC equ H'3FFD' ;crystal oscillator ; __CONFIG _CP_OFF & _PWRTE_ON & _WDT_OFF & _LP_OSC ;configure programmer directive w equ 0 ; register destination numbers. f equ 1 same equ 1 z equ 2 ; status flags zero equ 2 c equ 0 carry equ 0 count1 equ 0C ; wait counter ls digit file register C count2 equ 0D ; wait counter ms digit file register D portb equ 06 ; port b I/O register f6 porta equ 05 ; port a I/O register f5 status equ 03 ; status register f3 ; ; ; org 0 ; origin ; init movlw 0 tris portb ; set portb as outputs movwf portb ; set portb levels all low start btfss porta,1 ; check for light goto islight ;; blue tick bsf portb,0 ; Blue on bcf portb,2 ; tick bsf portb,2 ; tock bcf portb,2 ; tick bsf portb,2 ; tock call beep call beep bcf portb,0 ; Blue off call wait ;; blue tick bsf portb,0 ; Blue on bcf portb,2 ; tick bsf portb,2 ; tock bcf portb,2 ; tick bsf portb,2 ; tock call beep call beep bcf portb,0 ; Blue off call wait ;; blue tick bsf portb,0 ; Blue on bcf portb,2 ; tick bsf portb,2 ; tock bcf portb,2 ; tick bsf portb,2 ; tock call beep call beep bcf portb,0 ; Blue off call wait isdark call boop call boop call boop dark sleep sleep sleep sleep sleep sleep ;; blue tick bsf portb,0 ; Blue on bcf portb,2 ; tick bsf portb,2 ; tock bcf portb,2 ; tick bsf portb,2 ; tock call wait bcf portb,0 ; Blue off btfss porta,1 ; check for light goto dark islight call beep call beep call beep light sleep sleep ;; blue tick bsf portb,0 ; Blue on bcf portb,2 ; tick bsf portb,2 ; tock bcf portb,2 ; tick bsf portb,2 ; tock call wait bcf portb,2 ; tick bsf portb,2 ; tock bcf portb,2 ; tick bsf portb,2 ; tock call wait bcf portb,0 ; Blue off btfsc porta,1 ; check for dark goto light goto isdark beep movlw .20 movwf count1 bd1 movfw portb xorlw .4 movwf portb movfw count1 movwf count2 bd2 decfsz count2,same ; decrement and skip next line if zero goto bd2 ; if not zero decfsz count1 ; decrement count1 if count2 is zero goto bd1 ; do inside loop again if count2 nz bsf porta,1 ; A1 is beeper retlw 00 boop movlw .40 movwf count1 bp1 movfw portb xorlw .4 movwf portb movfw count1 sublw .41 movwf count2 bp2 decfsz count2,same ; decrement and skip next line if zero goto bp2 ; if not zero decfsz count1 ; decrement count1 if count2 is zero goto bp1 ; do inside loop again if count2 nz bsf porta,1 ; A1 is beeper retlw 00 wait movlw .12 ; load count1 with delay multiplier movwf count1 d1 movlw .12 ; load count2 with delay constant movwf count2 ; shorten these for the simulator d2 decfsz count2,same ; decrement and skip next line if zero goto d2 ; if not zero decfsz count1 ; decrement count1 if count2 is zero goto d1 ; do inside loop again if count2 nz retlw 00 END
xxx
 03/08/2007 |
Lisatx&Waterman placed it in 23 Kazoo | Texas – 57.52 miles | Visit Log |
 02/13/2007 |
catweb79 discovered it | Visit Log | |
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Discovered it from Lisa,TX,cool blinking TB. |
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| 02/08/2007 |
Reese_Texas discovered it | Visit Log | |
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Discovered this TB while in the possession of Lisatx. |
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 02/01/2007 |
Lisatx&Waterman retrieved it from I-45 Travel Bug Hotel | Texas | Visit Log |
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picked up tonight and will move it on its way. |
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| 01/10/2007 |
Boxer Pups placed it in I-45 Travel Bug Hotel | Texas – 166.64 miles | Visit Log |
| 01/01/2007 |
Boxer Pups retrieved it from Redwater City Park Cache | Texas | Visit Log |
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Great Travel Bug, we picked it up from the Redwater City Park and will take it with us to San Antonio, TX and warmer weather………..We will find a good cache for a drop off. The battery is still holding a good charge. Still blinks and chirps like crazy….. |
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| 11/02/2006 |
MrNezzer placed it in Redwater City Park Cache | Texas – 272.86 miles | Visit Log |
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Blinky is back on the road. |
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| 09/30/2006 |
MrNezzer retrieved it from Old Highway 67 TB Exchange | Arkansas | Visit Log |
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Blinky was clicking very sadly when found. After a few minutes in the sun he started blinking and clicking. |
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| 09/04/2006 |
hummer dude placed it in Old Highway 67 TB Exchange | Arkansas – 294.72 miles | Visit Log |
| 07/28/2006 |
hummer dude retrieved it from The Hole in the Tree | Texas | Visit Log |
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What a great TB We will take it on a trip and place it someplace neat. The blue light is doing just fine. |
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