| ??? 04/06/08 00:31 Read: times |
#152992 - stripboard circuit works! Responding to: ???'s previous message |
Hooray! Thanks for your help, mainly Richard. I took your warning about solderless breadboards to heart and rebuilt the circuit on stripboard with real soldered joints and it works. I just downloaded a simple LED counting program and it's running.
I probably had some poor connection or other problem before. I'm still a bit hazy on decoupling capacitors but don't let me take any more of your time, I can find somewhere with diagrams. I'm still on my 15MHz crystal and using the buffers shown in Fig 15-2 of the DS89C420 Ultra High Speed Flash Microcontroller Users Guide, controlling EA, PSEN and RST. I replaced the HC125 with a HC245 because that's what I've got to hand. The EA line doesn't go through a buffer but I could as I have six unused. Anyway it's working. Thanks very much everyone. |
| Topic | Author | Date |
| Take this up with the Maxim/Dallas support guys | 01/01/70 00:00 | |
| Why ? | 01/01/70 00:00 | |
| meaty PSU | 01/01/70 00:00 | |
| Mke sure you've got the right software | 01/01/70 00:00 | |
| Dallas MTK | 01/01/70 00:00 | |
| You've got to use exactly the parts they recommend | 01/01/70 00:00 | |
| no scope | 01/01/70 00:00 | |
| I'm not sure this is a deal-breaker ... | 01/01/70 00:00 | |
| same with DS89C420 | 01/01/70 00:00 | |
| decoupling | 01/01/70 00:00 | |
| I have no confidence at all in "breadboards" | 01/01/70 00:00 | |
| stripboard circuit works! | 01/01/70 00:00 | |
| about that bootloader ... | 01/01/70 00:00 | |
| that will not help | 01/01/70 00:00 | |
about those decoupling capacitors | 01/01/70 00:00 | |
| In case you're curious ... | 01/01/70 00:00 | |
| my DS89C450 experience was... | 01/01/70 00:00 | |
| What did you do? | 01/01/70 00:00 | |
| 8052.com SBC | 01/01/70 00:00 | |
| How considerate! | 01/01/70 00:00 | |
| progress ? | 01/01/70 00:00 | |
| programming circuit variations ... FIY | 01/01/70 00:00 | |
| DS89C430 boot loader | 01/01/70 00:00 |