Month: June 2017

ESP8266 WiFi power reduction – Avoiding network scan

Last month I wrote a series of posts about reducing the power consumption of the ESP8266, showing how I got the power consumption of a weather station down to 54 μAh per 5 minute reporting cycle.

At the end of that, I thought further improvements would be mainly tweaks and fine tuning, but Tobias wrote a comment explaining that it would be possible to avoid the initial network scan happening as part of the WiFi network association.  I’m happy to say that it is possible, and it works quite well indeed.

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Filtered form reference group lookup

Dynamics AX 2012 introduces built-in support for resolving and looking up linked records based on reference record IDs.

When adding a reference record ID field to a form, AX will add a reference group control instead of the reference record ID, and will show a selected set of fields from the referenced table.  See the posts about tree lookups for an example.

The reference group control also does lookups into the referenced table for selecting a new value.  However, by default this lookup is not filtered and will show all records in the referenced table.  Adding filtering is quite easy to do and it follows a similar pattern as regular table lookups.

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toolTipField() method not working

According to best practices, data-related code that accesses data from the database or otherwise would benefit multiple forms should be placed on the table.  Examples of this are display methods, validations and business logic to be executed on inserts, updates, deletes.

It would be logical to think tool tips would be included as well, and there is a record method called toolTipField() which can be overridden in your table.

Only problem is, it’s not working.  (At least not in 2012R3)  The code doesn’t even get called.

To work around it, add the tool tip code directly to your forms instead.  Not best practice according to the book, but what works will always trump what doesn’t…

Electronics basics: Ohm's law

This is a post to explain the basics of electronics, starting with Ohm’s law.

Ohm’s law describes the relationship between the voltage, current and resistance in a circuit, and it is one of the basic physical laws that controls how circuits work.

We need to understand this law in order to select the correct resistors to use in our circuits and to control how much current will flow.  We also need to know how much power our circuit will draw and how much power each component will dissipate.  Too much power and things will heat up too much, burning out.

And yes, this post does contain garden hoses…

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Dynamics AX error: The fetch type refresh cannot be used with forward only cursors

I recently encountered a strange error in AX, where on opening a particular form, AX would throw an error saying “The fetch type refresh cannot be used with forward only cursors”.

Restarting the AOS, running full X++ recompile and full CIL generation did not resolve the problem.

“The fetch type refresh cannot be used with forward only cursors”

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