RCharts+Leaflet+Shiny

Hi,

I'm trying to draw traffic cameras and air quality measure stations from
Madrid in a shiny app, using RCharts with leaflet
<https://github.com/ramnathv/rCharts>.

The author has many examples there, some doesn't work to me, some other
does. He has a very cool project working about citybikes in github too ->
https://github.com/ramnathv/bikeshare/ . This one works to me locally.

However, I'm not able to replicate the succeed on my project, I do render a
map in shiny, and I have added markers for some points, but now, I want to
use circles instead of markers because you can decide the color of it
depending on a variable.
I've never managed to plot these circles.

Since the problem involves data, libraries, and code, I share my app on
github:
https://github.com/ADIRSE/maddata

Most of the code is in the app/global.R file, at the bottom is the
plotMap() function.

The github project is a bit ahead of what I've deployed on shinyapps.io,
but you can have a glance of it too -> https://adirse.shinyapps.io/maddata/

Very welcome on advance!

Cheers,

Miguel