Wednesday, April 29, 2015

A bit of hardware tinkering

and not the usual computer hardware, that is.

I was asked to create muscle power to electricity demonstration device, basically pedal to light a light bulb. Easy enough, take a old exercise bike, strap an car alternator on it, some wires and a light. Right ?

The first prototype works as can be seen on this short video:



Next up is to make it more robust and figure out some foolproof way to handle the power pulse the alternator requires to get magnetized.

I'm thinking about using an Arduino (well, surprise!) to sense when the wheels are turning and if there is no power generated then give a short pulse to magnetize the alternator. Also voltage, current and watt display might be a nice addition.

Monday, April 20, 2015

Prestashop front-end stuck in maintenance mode ?

Back-end says shop is enabled but front-end is stubbornly stuck in maintenance mode ? Going crazy ? Don't panic!

Look into your Prestashop database, specifically the ps_configuration table.

select * from ps_configuration where ps_configuration.name = 'PS_SHOP_ENABLE';

You might get something like this:
 
+------------------+---------------+---------+----------------+-------+---------------------+---------------------+
| id_configuration | id_shop_group | id_shop | name           | value | date_add            | date_upd            |
+------------------+---------------+---------+----------------+-------+---------------------+---------------------+
|               30 |          NULL |    NULL | PS_SHOP_ENABLE | 1     | 0000-00-00 00:00:00 | 2015-04-17 13:24:22 | 
|              476 |          NULL |       1 | PS_SHOP_ENABLE | 0     | 2015-04-12 22:46:19 | 2015-04-12 22:46:19 | 
|              477 |          NULL |       6 | PS_SHOP_ENABLE | 0     | 2015-04-12 22:46:19 | 2015-04-12 22:46:19 | 
|              478 |          NULL |       7 | PS_SHOP_ENABLE | 0     | 2015-04-12 22:46:19 | 2015-04-12 22:46:19 | 
+------------------+---------------+---------+----------------+-------+---------------------+---------------------+

As you can see only one is enabled, other shops are not. The quick fix,  

update ps_configuration set value=1 where name='PS_SHOP_ENABLE';

should do the trick.