PICAXE Manual Section 1 - TechnoPujades - Free

www.picaxe.co.ukSection 1 42GETTING STARTEDHard-reset procedureThe download process involves the PICAXE microcontroller regularly checkingthe serial input line for a new download signal from the computer. This isautomatic and not noticed by the PICAXE user. However there can be rareoccasions when the PICAXE does not check the serial input line quickly enoughwhilst running its program. These situations can include:• Corrupt program in PICAXE (e.g. if power or cable removed part way througha new download)• Incorrect clock frequency (set by setfreq command)• Pause or wait commands longer than 5 seconds used in program.• Use of serin, infrain or keyin within program.Fortunately it is very simple to resolve this issue, as the very first thing anyPICAXE chip does on power reset is check for a new computer download.Therefore if you reset the PICAXE whilst a download is being started by thecomputer, the new download will always be recognised. This process is called ahard-reset.To perform a hard-reset using the reset switch (18, 28, 40 pin PICAXE):1) Press and hold down the reset switch.2) Click the PICAXE>Run menu to start a download.3) Wait until the progress-bar appears on screen.4) Wait 1 second then release the reset switch.To perform a hard reset using the power supply (all sizes):1) Disconnect the power supply.2) Wait until all power supply decoupling capacitors have discharged (can takeup to 30 seconds or more depending on circuit design).3) Click the PICAXE>Run menu to start a download.4) Wait until the progress-bar appears on screen.5) Reconnect the power supplyrevolution(c) Revolution Education Ltd. Email: info@rev-ed.co.uk Web: www.rev-ed.co.ukVersion 6.9 07/2009All rights reserved.42