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5301 Cold Fix | ATtiny Logger updates
A small number of 5301 displays exhibit a condition where they take a
short period (from seconds to minutes) to start working. These affected
displays will power up normally (see 5301 info)
and then show 10.<= (see image at right)
which normally indicates a rich condition.
Note: Other fault conditions can produce the same display.
The problem occurs because the display was designed, tested and expected to be used at room temperatures or above, and not the sub-zero temperatures often encountered in vehicles before they warm up in North American and European winters.
Fortunately, there is a relatively simple fix. The processor (a MicroChip 16F84A) needs updated firmware that changes the way one of the input pins is programmed, thus reducing the load seen by the LM358, allowing that chip to work within specifications at low temperatures.
You can either return your 16F84A chip and we will reflash and return it for free (we have decided not to charge postage as it would cost us more to handle the payment than the postage would cost us). Or you can send us a PayPal "instant" payment (US$6.60) and we'll send you a brand new 16F84A (with 16F84A-1.2 (5301) firmware).
If you know your 4 digit invoice number then please enter it before clicking on the PayPal button.
Alternatively you can send us an email using this link : I want the 5301-1.2 firmware, and we'll attach the latest firmware for you to reprogram the chip yourself. This will only work for you if you have access to a chip programmer, and if you can tell us your invoice or order number (the # number).
Early versions of the ATtiny logger software contained a few bugs that could cause the A/D channels (the logged user voltages) to randomly "swap places". As well, the latest software uses a different algorithm for determining the RPM, making it a little less prone to ignition noise that has been seen with a few vehicles. The image at right shows how this RPM noise (orange spikes) shows up in the logged data (refer to the software page for a description of this graph).
Note: version 1.0/1.1 is not affected by this fix as neither contain an ATtiny processor.
There are other issues relating to using the logger's RPM feature that I'll have more to say about here soon (15mar2003).
You can either return your ATtiny15L chip and we will reflash and return it for free (we have decided not to charge postage as it would cost us more to handle the payment than the postage would cost us). Or you can send us a PayPal "instant" payment (US$6.60) and we'll send you a brand new ATTiny15L (with Tiny15-1v5e firmware).
If you know your 4 digit invoice number then please enter it before clicking on the PayPal button.
Alternatively you can send us an email using this link : I want the Tiny15-1v5e firmware, and we'll attach the latest firmware for you to reprogram the chip yourself. This will only work for you if you have access to a chip programmer, and if you can tell us your invoice or order number (the # number).
There may also be another alternative way for you to return your chip to a location in the USA and for the cost of a stamped & self addressed envelope, have your ATTiny chip reflashed.
If you are programming your own ATtiny then follow these OSCCAL, fuse programming and Lock Bits programming steps to ensure correct operation. Read all the following information and understand it BEFORE trying to (re-)program the chip.
Program the OSCAL byte into EEPROM absolute address 0x3f. Note : If you are reprogramming an ATtiny for which the RS232 is currently working correctly (ie. OSCCAL byte is correctly programmed), then read the EEPROM contents and save as a file before doing any progrtamming, erase the ATtiny, then write back the saved EEPROM contents to preserve the exiting OSCCAL byte. Some ATtiny chips had bad factory OSCCAL bytes and we worked around this problem.
Note that ISP programming mode does NOT work with the pre-programmed ATtiny chips
as the pin 1 RESET input has been redefined as an A/D input and only HIGH VOLTAGE
programming mode will work
Last updated 19 March 2003
This document is © Copyright Tech Edge 2003
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