| ??? 04/25/07 13:16 Read: times |
#137924 - been there, done that Responding to: ???'s previous message |
For just two devices
comes under the heading "famous last wordss" I can not recall the number of times I have been told 'just' and found out that the 'just' was valid for about a day or a week. We have, re debuuging and such, from time to time discussed "defensive programming", I would like to introduce the concept of defensive design Defensive design, to me means that, if I am told to have two ports, I will make it (expandable to) 4 ports from the onset, if I am told that 12MHz is fast enough, I will chose a 24MHz processor. NOW, before anyone start hollering 'cost' let me answer a) defensive design as discussed above refer only in a limited way to 'self contained' units (no external I/O) and especially not to toys, whether 'toys' are playthings or 'cheap crap'. b) the cost applying the above at volume will be about $0.10 per unit but will cost, at least, $50.00 in shipping, parts and labor per unit when you have to bring them in and refurbish them. c) when you have shipped a sufficient number of units and got plenty of customer feedback, instead of the saleamans 'just' you can, possibly change to the cheaper parts. I will, in addition to here, start this in a separate thread. Erik |
| Topic | Author | Date |
| multiple 8052 communication with PC | 01/01/70 00:00 | |
| RS485 | 01/01/70 00:00 | |
| More COM: Ports | 01/01/70 00:00 | |
| Further additional COM: ports | 01/01/70 00:00 | |
| multiple 8052 communication with PC | 01/01/70 00:00 | |
| Simple solution | 01/01/70 00:00 | |
| Recipe for a short circuit? | 01/01/70 00:00 | |
| Not on a standard 8051? | 01/01/70 00:00 | |
| whether that is a problem is for the OP to determi | 01/01/70 00:00 | |
| protocol ?? | 01/01/70 00:00 | |
| yes - no - see above | 01/01/70 00:00 | |
| master slave PC performance | 01/01/70 00:00 | |
| multi-GHz PC can get a lot done in a few ms! | 01/01/70 00:00 | |
| Slave comms controller? | 01/01/70 00:00 | |
| expanding on th above | 01/01/70 00:00 | |
| For just two devices | 01/01/70 00:00 | |
| been there, done that | 01/01/70 00:00 | |
In this case... | 01/01/70 00:00 | |
| Interrupt Request? | 01/01/70 00:00 | |
| not really | 01/01/70 00:00 | |
| Not on a PC | 01/01/70 00:00 | |
| Not that it can't be done | 01/01/70 00:00 | |
| Another recipe is a ring!!! | 01/01/70 00:00 | |
| sure, if you have all the time in the world | 01/01/70 00:00 |